No More Learning

2

In sanguineous animals the homogeneous or uniform part most
universally found is the blood, and its habitat the vein; next in
degree of universality, their analogues, lymph and fibre, and, that
which chiefly constitutes the frame of animals, flesh and whatsoever
in the several parts is analogous to flesh; then bone, and parts
that are analogous to bone, as fish-bone and gristle; and then, again,
skin, membrane, sinew, hair, nails, and whatever corresponds to these;
and, furthermore, fat, suet, and the excretions: and the excretions
are dung, phlegm, yellow bile, and black bile.

Now, as the nature of blood and the nature of the veins have
all the appearance of being primitive, we must discuss their
properties first of all, and all the more as some previous writers
have treated them very unsatisfactorily. And the cause of the
ignorance thus manifested is the extreme difficulty experienced in the
way of observation. For in the dead bodies of animals the nature of
the chief veins is undiscoverable, owing to the fact that they
collapse at once when the blood leaves them; for the blood pours out
of them in a stream, like liquid out of a vessel, since there is no
blood separately situated by itself, except a little in the heart, but
it is all lodged in the veins. In living animals it is impossible to
inspect these parts, for of their very nature they are situated inside
the body and out of sight. For this reason anatomists who have carried
on their investigations on dead bodies in the dissecting room have
failed to discover the chief roots of the veins, while those who
have narrowly inspected bodies of living men reduced to extreme
attenuation have arrived at conclusions regarding the origin of the
veins from the manifestations visible externally. Of these
investigators, Syennesis, the physician of Cyprus, writes as follows:-

'The big veins run thus:-from the navel across the loins, along
the back, past the lung, in under the breasts; one from right to left,
and the other from left to right; that from the left, through the
liver to the kidney and the testicle, that from the right, to the
spleen and kidney and testicle, and from thence to the penis. '
Diogenes of Apollonia writes thus:-

'The veins in man are as follows:-There are two veins
pre-eminent in magnitude. These extend through the belly along the
backbone, one to right, one to left; either one to the leg on its
own side, and upwards to the head, past the collar bones, through
the throat. From these, veins extend all over the body, from that on
the right hand to the right side and from that on the left hand to the
left side; the most important ones, two in number, to the heart in the
region of the backbone; other two a little higher up through the chest
in underneath the armpit, each to the hand on its side: of these
two, one being termed the vein splenitis, and the other the vein
hepatitis. Each of the pair splits at its extremity; the one
branches in the direction of the thumb and the other in the
direction of the palm; and from these run off a number of minute veins
branching off to the fingers and to all parts of the hand. Other
veins, more minute, extend from the main veins; from that on the right
towards the liver, from that on the left towards the spleen and the
kidneys. The veins that run to the legs split at the juncture of the
legs with the trunk and extend right down the thigh. The largest of
these goes down the thigh at the back of it, and can be discerned
and traced as a big one; the second one runs inside the thigh, not
quite as big as the one just mentioned. After this they pass on
along the knee to the shin and the foot (as the upper veins were
described as passing towards the hands), and arrive at the sole of the
foot, and from thence continue to the toes. Moreover, many delicate
veins separate off from the great veins towards the stomach and
towards the ribs.

'The veins that run through the throat to the head can be
discerned and traced in the neck as large ones; and from each one of
the two, where it terminates, there branch off a number of veins to
the head; some from the right side towards the left, and some from the
left side towards the right; and the two veins terminate near to
each of the two ears. There is another pair of veins in the neck
running along the big vein on either side, slightly less in size
than the pair just spoken of, and with these the greater part of the
veins in the head are connected. This other pair runs through the
throat inside; and from either one of the two there extend veins in
underneath the shoulder blade and towards the hands; and these
appear alongside the veins splenitis and hepatitis as another pair
of veins smaller in size. When there is a pain near the surface of the
body, the physician lances these two latter veins; but when the pain
is within and in the region of the stomach he lances the veins
splenitis and hepatitis. And from these, other veins depart to run
below the breasts.

'There is also another pair running on each side through the
spinal marrow to the testicles, thin and delicate. There is,
further, a pair running a little underneath the cuticle through the
flesh to the kidneys, and these with men terminate at the testicle,
and with women at the womb. These veins are termed the spermatic
veins. The veins that leave the stomach are comparatively broad just
as they leave; but they become gradually thinner, until they change
over from right to left and from left to right.

'Blood is thickest when it is imbibed by the fleshy parts; when
it is transmitted to the organs above-mentioned, it becomes thin,
warm, and frothy. '

3

Such are the accounts given by Syennesis and Diogenes. Polybus
writes to the following effect:-

'There are four pairs of veins. The first extends from the back of
the head, through the neck on the outside, past the backbone on either
side, until it reaches the loins and passes on to the legs, after
which it goes on through the shins to the outer side of the ankles and
on to the feet. And it is on this account that surgeons, for pains
in the back and loin, bleed in the ham and in the outer side of the
ankle. Another pair of veins runs from the head, past ears, through
the neck; which veins are termed the jugular veins. This pair goes
on inside along the backbone, past the muscles of the loins, on to the
testicles, and onwards to the thighs, and through the inside of the
hams and through the shins down to the inside of the ankles and to the
feet; and for this reason, surgeons, for pains in the muscles of the
loins and in the testicles, bleed on the hams and the inner side of
the ankles. The third pair extends from the temples, through the neck,
in underneath the shoulder-blades, into the lung; those from right
to left going in underneath the breast and on to the spleen and the
kidney; those from left to right running from the lung in underneath
the breast and into the liver and the kidney; and both terminate in
the fundament. The fourth pair extend from the front part of the
head and the eyes in underneath the neck and the collar-bones; from
thence they stretch on through the upper part of the upper arms to the
elbows and then through the fore-arms on to the wrists and the
jointings of the fingers, and also through the lower part of the
upper-arms to the armpits, and so on, keeping above the ribs, until
one of the pair reaches the spleen and the other reaches the liver;
and after this they both pass over the stomach and terminate at the
penis. '

The above quotations sum up pretty well the statements of all
previous writers. Furthermore, there are some writers on Natural
History who have not ventured to lay down the law in such precise
terms as regards the veins, but who all alike agree in assigning the
head and the brain as the starting-point of the veins. And in this
opinion they are mistaken.

The investigation of such a subject, as has been remarked, is one
fraught with difficulties; but, if any one be keenly interested in the
matter, his best plan will be to allow his animals to starve to
emaciation, then to strangle them on a sudden, and thereupon to
prosecute his investigations.

We now proceed to give particulars regarding the properties and
functions of the veins. There are two blood-vessels in the thorax by
the backbone, and lying to its inner side; and of these two the larger
one is situated to the front, and the lesser one is to the rear of it;
and the larger is situated rather to the right hand side of the
body, and the lesser one to the left; and by some this vein is
termed the 'aorta', from the fact that even in dead bodies part of
it is observed to be full of air. These blood-vessels have their
origins in the heart, for they traverse the other viscera, in whatever
direction they happen to run, without in any way losing their
distinctive characteristic as blood-vessels, whereas the heart is as
it were a part of them (and that too more in respect to the
frontward and larger one of the two), owing to the fact that these two
veins are above and below, with the heart lying midway.

The heart in all animals has cavities inside it. In the case of
the smaller animals even the largest of the chambers is scarcely
discernible; the second larger is scarcely discernible in animals of
medium size; but in the largest animals all three chambers are
distinctly seen. In the heart then (with its pointed end directed
frontwards, as has been observed) the largest of the three chambers is
on the right-hand side and highest up; the least one is on the
left-hand side; and the medium-sized one lies in betwixt the other
two; and the largest one of the three chambers is a great deal
larger than either of the two others. All three, however, are
connected with passages leading in the direction of the lung, but
all these communications are indistinctly discernible by reason of
their minuteness, except one.

The great blood-vessel, then, is attached to the biggest of the
three chambers, the one that lies uppermost and on the right-hand
side; it then extends right through the chamber, coming out as
blood-vessel again; just as though the cavity of the heart were a part
of the vessel, in which the blood broadens its channel as a river that
widens out in a lake. The aorta is attached to the middle chamber;
only, by the way, it is connected with it by much narrower pipe.

The great blood-vessel then passes through the heart (and runs
from the heart into the aorta). The great vessel looks as though
made of membrane or skin, while the aorta is narrower than it, and
is very sinewy; and as it stretches away to the head and to the
lower parts it becomes exceedingly narrow and sinewy.

First of all, then, upwards from the heart there stretches a
part of the great blood-vessel towards the lung and the attachment
of the aorta, a part consisting of a large undivided vessel. But there
split off from it two parts; one towards the lung and the other
towards the backbone and the last vertebra of the neck.

The vessel, then, that extends to the lung, as the lung itself
is duplicate, divides at first into two; and then extends along by
every pipe and every perforation, greater along the greater ones,
lesser along the less, so continuously that it is impossible to
discern a single part wherein there is not perforation and vein; for
the extremities are indistinguishable from their minuteness, and in
point of fact the whole lung appears to be filled with blood.

The branches of the blood-vessels lie above the tubes that
extend from the windpipe. And that vessel which extends to the
vertebra of the neck and the backbone, stretches back again along
the backbone; as Homer represents in the lines:-

(Antilochus, as Thoon turned him round),

Transpierc'd his back with a dishonest wound;

The hollow vein that to the neck extends,

Along the chine, the eager javelin rends.

From this vessel there extend small blood-vessels at each rib
and each vertebra; and at the vertebra above the kidneys the vessel
bifurcates. And in the above way the parts branch off from the great
blood-vessel.

But up above all these, from that part which is connected with the
heart, the entire vein branches off in two directions. For its
branches extend to the sides and to the collarbones, and then pass on,
in men through the armpits to the arms, in quadrupeds to the forelegs,
in birds to the wings, and in fishes to the upper or pectoral fins.
(See diagram. ) The trunks of these veins, where they first branch
off, are called the 'jugular' veins; and, where they branch off to
the neck the great vein run alongside the windpipe; and,
occasionally, if these veins are pressed externally, men, though not
actually choked, become insensible, shut their eyes, and fall flat on
the ground. Extending in the way described and keeping the windpipe
in betwixt them, they pass on until they reach the ears at the
junction of the lower jaw with the skull. Hence again they branch off
into four veins, of which one bends back and descends through the
neck and the shoulder, and meets the previous branching off of the
vein at the bend of the arm, while the rest of it terminates at the
hand and fingers. (See diagram. )

Each vein of the other pair stretches from the region of the ear
to the brain, and branches off in a number of fine and delicate
veins into the so-called meninx, or membrane, which surrounds the
brain. The brain itself in all animals is destitute of blood, and no
vein, great or small, holds its course therein. But of the remaining
veins that branch off from the last mentioned vein some envelop the
head, others close their courses in the organs of sense and at the
roots of the teeth in veins exceedingly fine and minute.

4

And in like manner the parts of the lesser one of the two chief
blood-vessels, designated the aorta, branch off, accompanying the
branches from the big vein; only that, in regard to the aorta, the
passages are less in size, and the branches very considerably less
than are those of the great vein. So much for the veins as observed in
the regions above the heart.

The part of the great vein that lies underneath the heart
extends, freely suspended, right through the midriff, and is united
both to the aorta and the backbone by slack membranous communications.
From it one vein, short and wide, extends through the liver, and
from it a number of minute veins branch off into the liver and
disappear. From the vein that passes through the liver two branches
separate off, of which one terminates in the diaphragm or so-called
midriff, and the other runs up again through the armpit into the right
arm and unites with the other veins at the inside of the bend of the
arm; and it is in consequence of this local connexion that, when the
surgeon opens this vein in the forearm, the patient is relieved of
certain pains in the liver; and from the left-hand side of it there
extends a short but thick vein to the spleen and the little veins
branching off it disappear in that organ. Another part branches off
from the left-hand side of the great vein, and ascends, by a course
similar to the course recently described, into the left arm; only that
the ascending vein in the one case is the vein that traverses the
liver, while in this case it is distinct from the vein that runs
into the spleen. Again, other veins branch off from the big vein;
one to the omentum, and another to the pancreas, from which vein run a
number of veins through the mesentery. All these veins coalesce in a
single large vein, along the entire gut and stomach to the oesophagus;
about these parts there is a great ramification of branch veins.

As far as the kidneys, each of the two remaining undivided, the
aorta and the big vein extend; and here they get more closely attached
to the backbone, and branch off, each of the two, into a A shape,
and the big vein gets to the rear of the aorta. But the chief
attachment of the aorta to the backbone takes place in the region of
the heart; and the attachment is effected by means of minute and
sinewy vessels. The aorta, just as it draws off from the heart, is a
tube of considerable volume, but, as it advances in its course, it
gets narrower and more sinewy. And from the aorta there extend veins
to the mesentery just like the veins that extend thither from the
big vein, only that the branches in the case of the aorta are
considerably less in magnitude; they are, indeed, narrow and
fibrillar, and they end in delicate hollow fibre-like veinlets.

There is no vessel that runs from the aorta into the liver or
the spleen.

From each of the two great blood-vessels there extend branches
to each of the two flanks, and both branches fasten on to the bone.
Vessels also extend to the kidneys from the big vein and the aorta;
only that they do not open into the cavity of the organ, but their
ramifications penetrate into its substance. From the aorta run two
other ducts to the bladder, firm and continuous; and there are other
ducts from the hollow of the kidneys, in no way communicating with the
big vein. From the centre of each of the two kidneys springs a
hollow sinewy vein, running along the backbone right through the
loins; by and by each of the two veins first disappears in its own
flank, and soon afterwards reappears stretching in the direction of
the flank. The extremities of these attach to the bladder, and also in
the male to the penis and in the female to the womb. From the big vein
no vein extends to the womb, but the organ is connected with the aorta
by veins numerous and closely packed.

Furthermore, from the aorta and the great vein at the points of
divarication there branch off other veins. Some of these run to the
groins-large hollow veins-and then pass on down through the legs and
terminate in the feet and toes. And, again, another set run through
the groins and the thighs cross-garter fashion, from right to left and
from left to right, and unite in the hams with the other veins.

In the above description we have thrown light upon the course of
the veins and their points of departure.

In all sanguineous animals the case stands as here set forth in
regard to the points of departure and the courses of the chief
veins. But the description does not hold equally good for the entire
vein-system in all these animals. For, in point of fact, the organs
are not identically situated in them all; and, what is more, some
animals are furnished with organs of which other animals are
destitute. At the same time, while the description so far holds
good, the proof of its accuracy is not equally easy in all cases,
but is easiest in the case of animals of considerable magnitude and
supplied abundantly with blood. For in little animals and those
scantily supplied with blood, either from natural and inherent
causes or from a prevalence of fat in the body, thorough accuracy in
investigation is not equally attainable; for in the latter of these
creatures the passages get clogged, like water-channels choked with
slush; and the others have a few minute fibres to serve instead of
veins. But in all cases the big vein is plainly discernible, even in
creatures of insignificant size.

5

The sinews of animals have the following properties. For these
also the point of origin is the heart; for the heart has sinews within
itself in the largest of its three chambers, and the aorta is a
sinew-like vein; in fact, at its extremity it is actually a sinew, for
it is there no longer hollow, and is stretched like the sinews where
they terminate at the jointings of the bones. Be it remembered,
however, that the sinews do not proceed in unbroken sequence from
one point of origin, as do the blood-vessels.

For the veins have the shape of the entire body, like a sketch
of a mannikin; in such a way that the whole frame seems to be filled
up with little veins in attenuated subjects-for the space occupied
by flesh in fat individuals is filled with little veins in thin
ones-whereas the sinews are distributed about the joints and the
flexures of the bones. Now, if the sinews were derived in unbroken
sequence from a common point of departure, this continuity would be
discernible in attenuated specimens.

In the ham, or the part of the frame brought into full play in the
effort of leaping, is an important system of sinews; and another
sinew, a double one, is that called 'the tendon', and others are those
brought into play when a great effort of physical strength is
required; that is to say, the epitonos or back-stay and the
shoulder-sinews. Other sinews, devoid of specific designation, are
situated in the region of the flexures of the bones; for all the bones
that are attached to one another are bound together by sinews, and a
great quantity of sinews are placed in the neighbourhood of all the
bones. Only, by the way, in the head there is no sinew; but the head
is held together by the sutures of the bones.

Sinew is fissile lengthwise, but crosswise it is not easily
broken, but admits of a considerable amount of hard tension. In
connexion with sinews a liquid mucus is developed, white and
glutinous, and the organ, in fact, is sustained by it and appears to
be substantially composed of it. Now, vein may be submitted to the
actual cautery, but sinew, when submitted to such action, shrivels
up altogether; and, if sinews be cut asunder, the severed parts will
not again cohere. A feeling of numbness is incidental only to parts of
the frame where sinew is situated.

There is a very extensive system of sinews connected severally
with the feet, the hands, the ribs, the shoulder-blades, the neck, and
the arms.

All animals supplied with blood are furnished with sinews; but
in the case of animals that have no flexures to their limbs, but
are, in fact, destitute of either feet or hands, the sinews are fine
and inconspicuous; and so, as might have been anticipated, the
sinews in the fish are chiefly discernible in connexion with the fin.

6

The ines (or fibrous connective tissue) are a something
intermediate between sinew and vein. Some of them are supplied with
fluid, the lymph; and they pass from sinew to vein and from vein to
sinew. There is another kind of ines or fibre that is found in
blood, but not in the blood of all animals alike. If this fibre be
left in the blood, the blood will coagulate; if it be removed or
extracted, the blood is found to be incapable of coagulation. While,
however, this fibrous matter is found in the blood of the great
majority of animals, it is not found in all. For instance, we fail
to find it in the blood of the deer, the roe, the antelope, and some
other animals; and, owing to this deficiency of the fibrous tissue,
the blood of these animals does not coagulate to the extent observed
in the blood of other animals. The blood of the deer coagulates to
about the same extent as that of the hare: that is to the blood in
either case coagulates, but not into a stiff or jelly-like
substance, like the blood of ordinary animals, but only into a flaccid
consistency like that of milk which is not subjected to the action
of rennet. The blood of the antelope admits of a firmer consistency in
coagulation; for in this respect it resembles, or only comes a
little short of, the blood of sheep. Such are the properties of
vein, sinew, and fibrous tissue.

7

The bones in animals are all connected with one single bone, and
are interconnected, like the veins, in one unbroken sequence; and
there is no instance of a bone standing apart by itself. In all
animals furnished with bones, the spine or backbone is the point of
origin for the entire osseous system. The spine is composed of
vertebrae, and it extends from the head down to the loins. The
vertebrae are all perforated, and, above, the bony portion of the head
is connected with the topmost vertebrae, and is designated the
'skull'. And the serrated lines on the skull are termed 'sutures'.

The skull is not formed alike in all animals. In some animals
the skull consists of one single undivided bone, as in the case of the
dog; in others it is composite in structure, as in man; and in the
human species the suture is circular in the female, while in the
male it is made up of three separate sutures, uniting above in
three-corner fashion; and instances have been known of a man's skull
being devoid of suture altogether. The skull is composed not of four
bones, but of six; two of these are in the region of the ears, small
in comparison with the other four. From the skull extend the jaws,
constituted of bone. (Animals in general move the lower jaw; the river
crocodile is the only animal that moves the upper one. ) In the jaws is
the tooth-system; and the teeth are constituted of bone, and are
half-way perforated; and the bone in question is the only kind of bone
which it is found impossible to grave with a graving tool.

On the upper part of the course of the backbone are the
collar-bones and the ribs. The chest rests on ribs; and these ribs
meet together, whereas the others do not; for no animal has bone in
the region of the stomach. Then come the shoulder-bones, or
blade-bones, and the arm-bones connected with these, and the bones
in the hands connected with the bones of the arms. With animals that
have forelegs, the osseous system of the foreleg resembles that of the
arm in man.

Below the level of the backbone, after the haunch-bone, comes
the hip-socket; then the leg-bones, those in the thighs and those in
the shins, which are termed colenes or limb-bones, a part of which
is the ankle, while a part of the same is the so-called 'plectrum'
in those creatures that have an ankle; and connected with these
bones are the bones in the feet.

Now, with all animals that are supplied with blood and furnished
with feet, and are at the same time viviparous, the bones do not
differ greatly one from another, but only in the way of relative
hardness, softness, or magnitude. A further difference, by the way, is
that in one and the same animal certain bones are supplied with
marrow, while others are destitute of it. Some animals might on casual
observation appear to have no marrow whatsoever in their bones: as
is the case with the lion, owing to his having marrow only in small
amount, poor and thin, and in very few bones; for marrow is found in
his thigh and armbones. The bones of the lion are exceptionally
hard; so hard, in fact, that if they are rubbed hard against one
another they emit sparks like flint-stones. The dolphin has bones, and
not fish-spine.

Of the other animals supplied with blood, some differ but
little, as is the case with birds; others have systems analogous, as
fishes; for viviparous fishes, such as the cartilaginous species,
are gristle-spined, while the ovipara have a spine which corresponds
to the backbone in quadrupeds. This exceptional property has been
observed in fishes, that in some of them there are found delicate
spines scattered here and there throughout the fleshy parts. The
serpent is similarly constructed to the fish; in other words, his
backbone is spinous. With oviparous quadrupeds, the skeleton of the
larger ones is more or less osseous; of the smaller ones, more or less
spinous. But all sanguineous animals have a backbone of either one
kind or other: that is, composed either of bone or of spine.

The other portions of the skeleton are found in some animals and
not found in others, but the presence or the absence of this and
that part carries with it, as a matter of course, the presence or
the absence of the bones or the spines corresponding to this or that
part. For animals that are destitute of arms and legs cannot be
furnished with limb-bones: and in like manner with animals that have
the same parts, but yet have them unlike in form; for in these animals
the corresponding bones differ from one another in the way of relative
excess or relative defect, or in the way of analogy taking the place
of identity. So much for the osseous or spinous systems in animals.

8

Gristle is of the same nature as bone, but differs from it in
the way of relative excess or relative defect. And just like bone,
cartilage also, if cut, does not grow again. In terrestrial viviparous
sanguinea the gristle formations are unperforated, and there is no
marrow in them as there is in bones; in the selachia, however--for, be
it observed, they are gristle-spined--there is found in the case of
the flat space in the region of the backbone, a gristle-like substance
analogous to bone, and in this gristle-like substance there is a
liquid resembling marrow. In viviparous animals furnished with feet,
gristle formations are found in the region of the ears, in the
nostrils, and around certain extremities of the bones.

9

Furthermore, there are parts of other kinds, neither identical
with, nor altogether diverse from, the parts above enumerated: such as
nails, hooves, claws, and horns; and also, by the way, beaks, such
as birds are furnished with-all in the several animals that are
furnished therewithal. All these parts are flexible and fissile; but
bone is neither flexible nor fissile, but frangible.

And the colours of horns and nails and claw and hoof follow the
colour of the skin and the hair. For according as the skin of an
animal is black, or white, or of medium hue, so are the horns, the
claws, or the hooves, as the case may be, of hue to match. And it is
the same with nails. The teeth, however, follow after the bones.
Thus in black men, such as the Aethiopians and the like, the teeth and
bones are white, but the nails are black, like the whole of the skin.

Horns in general are hollow at their point of attachment to the
bone which juts out from the head inside the horn, but they have a
solid portion at the tip, and they are simple and undivided in
structure. In the case of the stag alone of all animals the horns
are solid throughout, and ramify into branches (or antlers). And,
whereas no other animal is known to shed its horns, the deer sheds its
horns annually, unless it has been castrated; and with regard to the
effects of castration in animals we shall have much to say
hereafter. Horns attach rather to the skin than to the bone; which
will account for the fact that there are found in Phrygia and
elsewhere cattle that can move their horns as freely as their ears.

Of animals furnished with nails-and, by the way, all animals
have nails that have toes, and toes that have feet, except the
elephant; and the elephant has toes undivided and slightly
articulated, but has no nails whatsoever--of animals furnished with
nails, some are straight-nailed, like man; others are crooked
nailed, as the lion among animals that walk, and the eagle among
animals that fly.

10

The following are the properties of hair and of parts analogous to
hair, and of skin or hide. All viviparous animals furnished with
feet have hair; all oviparous animals furnished with feet have
horn-like tessellates; fishes, and fishes only, have scales-that is,
such oviparous fishes as have the crumbling egg or roe. For of the
lanky fishes, the conger has no such egg, nor the muraena, and the eel
has no egg at all.

The hair differs in the way of thickness and fineness, and of
length, according to the locality of the part in which it is found,
and according to the quality of skin or hide on which it grows. For,
as a general rule, the thicker the hide, the harder and the thicker is
the hair; and the hair is inclined to grow in abundance and to a great
length in localities of the bodies hollow and moist, if the localities
be fitted for the growth of hair at all. The facts are similar in
the case of animals whether coated with scales or with tessellates.
With soft-haired animals the hair gets harder with good feeding, and
with hard-haired or bristly animals it gets softer and scantier from
the same cause. Hair differs in quality also according to the relative
heat or warmth of the locality: just as the hair in man is hard in
warm places and soft in cold ones. Again, straight hair is inclined to
be soft, and curly hair to be bristly.

11

Hair is naturally fissile, and in this respect it differs in
degree in diverse animals. In some animals the hair goes on
gradually hardening into bristle until it no longer resembles hair but
spine, as in the case of the hedgehog. And in like manner with the
nails; for in some animals the nail differs as regards solidity in
no way from bone.

Of all animals man has the most delicate skin: that is, if we take
into consideration his relative size. In the skin or hide of all
animals there is a mucous liquid, scanty in some animals and plentiful
in others, as, for instance, in the hide of the ox; for men
manufacture glue out of it. (And, by the way, in some cases glue is
manufactured from fishes also. ) The skin, when cut, is in itself
devoid of sensation; and this is especially the case with the skin
on the head, owing to there being no flesh between it and the skull.
And wherever the skin is quite by itself, if it be cut asunder, it
does not grow together again, as is seen in the thin part of the
jaw, in the prepuce, and the eyelid. In all animals the skin is one of
the parts that extends continuous and unbroken, and it comes to a stop
only where the natural ducts pour out their contents, and at the mouth
and nails.

All sanguineous animals, then, have skin; but not all such animals
have hair, save only under the circumstances described above. The hair
changes its colour as animals grow old, and in man it turns white or
grey. With animals, in general, the change takes place, but not very
obviously, or not so obviously as in the case of the horse. Hair turns
grey from the point backwards to the roots. But, in the majority of
cases, grey hairs are white from the beginning; and this is a proof
that greyness of hair does not, as some believe to be the case,
imply withering or decrepitude, for no part is brought into
existence in a withered or decrepit condition.

In the eruptive malady called the white-sickness all the hairs get
grey; and instances have been known where the hair became grey while
the patients were ill of the malady, whereas the grey hairs shed off
and black ones replaced them on their recovery. (Hair is more apt to
turn grey when it is kept covered than when exposed to the action of
the outer air. ) In men, the hair over the temples is the first to turn
grey, and the hair in the front grows grey sooner than the hair at the
back; and the hair on the pubes is the last to change colour.

Some hairs are congenital, others grow after the maturity of the
animal; but this occurs in man only. The congenital hairs are on the
head, the eyelids, and the eyebrows; of the later growths the hairs on
the pubes are the first to come, then those under the armpits, and,
thirdly, those on the chin; for, singularly enough, the regions
where congenital growths and the subsequent growths are found are
equal in number. The hair on the head grows scanty and sheds out to
a greater extent and sooner than all the rest. But this remark applies
only to hair in front; for no man ever gets bald at the back of his
head. Smoothness on the top of the head is termed 'baldness', but
smoothness on the eyebrows is denoted by a special term which means
'forehead-baldness'; and neither of these conditions of baldness
supervenes in a man until he shall have come under the influence of
sexual passion. For no boy ever gets bald, no woman, and no
castrated man. In fact, if a man be castrated before reaching puberty,
the later growths of hair never come at all; and, if the operation
take place subsequently, the aftergrowths, and these only, shed off;
or, rather, two of the growths shed off, but not that on the pubes.

Women do not grow hairs on the chin; except that a scanty beard
grows on some women after the monthly courses have stopped; and
similar phenomenon is observed at times in priestesses in Caria, but
these cases are looked upon as portentous with regard to coming
events. The other after-growths are found in women, but more scanty
and sparse. Men and women are at times born constitutionally and
congenitally incapable of the after-growths; and individuals that
are destitute even of the growth upon the pubes are constitutionally
impotent.

Hair as a rule grows more or less in length as the wearer grows in
age; chiefly the hair on the head, then that in the beard, and fine
hair grows longest of all.
With some people as they grow old the
eyebrows grow thicker, to such an extent that they have to be cut off;
and this growth is owing to the fact that the eyebrows are situated at
a conjuncture of bones, and these bones, as age comes on, draw apart
and exude a gradual increase of moisture or rheum. The eyelashes do
not grow in size, but they shed when the wearer comes first under
the influence of sexual feelings, and shed all the quicker as this
influence is the more powerful; and these are the last hairs to grow
grey.

Hairs if plucked out before maturity grow again; but they do not
grow again if plucked out afterwards. Every hair is supplied with a
mucous moisture at its root, and immediately after being plucked out
it can lift light articles if it touch them with this mucus.

Animals that admit of diversity of colour in the hair admit of a
similar diversity to start with in the skin and in the cuticle of
the tongue.

In some cases among men the upper lip and the chin is thickly
covered with hair, and in other cases these parts are smooth and the
cheeks are hairy; and, by the way, smooth-chinned men are less
inclined than bearded men to baldness.

The hair is inclined to grow in certain diseases, especially in
consumption, and in old age, and after death; and under these
circumstances the hair hardens concomitantly with its growth, and
the same duplicate phenomenon is observable in respect of the nails.

In the case of men of strong sexual passions the congenital
hairs shed the sooner, while the hairs of the after-growths are the
quicker to come. When men are afflicted with varicose veins they are
less inclined to take on baldness; and if they be bald when they
become thus afflicted, they have a tendency to get their hair again.

If a hair be cut, it does not grow at the point of section; but it
gets longer by growing upward from below. In fishes the scales grow
harder and thicker with age, and when the amimal gets emaciated or
is growing old the scales grow harder. In quadrupeds as they grow
old the hair in some and the wool in others gets deeper but scantier
in amount: and the hooves or claws get larger in size; and the same is
the case with the beaks of birds. The claws also increase in size,
as do also the nails.

12

With regard to winged animals, such as birds, no creature is
liable to change of colour by reason of age, excepting the crane.
The wings of this bird are ash-coloured at first, but as it grows
old the wings get black. Again, owing to special climatic
influences, as when unusual frost prevails, a change is sometimes
observed to take place in birds whose plumage is of one uniform
colour; thus, birds that have dusky or downright black plumage turn
white or grey, as the raven, the sparrow, and the swallow; but no case
has ever yet been known of a change of colour from white to black.
(Further, most birds change the colour of their plumage at different
seasons of the year, so much so that a man ignorant of their habits
might be mistaken as to their identity. ) Some animals change the
colour of their hair with a change in their drinking-water, for in
some countries the same species of animal is found white in one
district and black in another. And in regard to the commerce of the
sexes, water in many places is of such peculiar quality that rams,
if they have intercourse with the female after drinking it, beget
black lambs, as is the case with the water of the Psychrus
(so-called from its coldness), a river in the district of Assyritis in
the Chalcidic Peninsula, on the coast of Thrace; and in Antandria
there are two rivers of which one makes the lambs white and the
other black. The river Scamander also has the reputation of making
lambs yellow, and that is the reason, they say, why Homer designates
it the 'Yellow River. ' Animals as a general rule have no hair on their
internal surfaces, and, in regard to their extremities, they have hair
on the upper, but not on the lower side.

The hare, or dasypod, is the only animal known to have hair inside
its mouth and underneath its feet. Further, the so-called mousewhale
instead of teeth has hairs in its mouth resembling pigs' bristles.

Hairs after being cut grow at the bottom but not at the top; if
feathers be cut off, they grow neither at top nor bottom, but shed and
fall out. Further, the bee's wing will not grow again after being
plucked off, nor will the wing of any creature that has undivided
wings. Neither will the sting grow again if the bee lose it, but the
creature will die of the loss.

13

In all sanguineous animals membranes are found. And membrane
resembles a thin close-textured skin, but its qualities are different,
as it admits neither of cleavage nor of extension. Membrane envelops
each one of the bones and each one of the viscera, both in the
larger and the smaller animals; though in the smaller animals the
membranes are indiscernible from their extreme tenuity and minuteness.
The largest of all the membranes are the two that surround the
brain, and of these two the one that lines the bony skull is
stronger and thicker than the one that envelops the brain; next in
order of magnitude comes the membrane that encloses the heart. If
membrane be bared and cut asunder it will not grow together again, and
the bone thus stripped of its membrane mortifies.

14

The omentum or caul, by the way, is membrane. All sanguineous
animals are furnished with this organ; but in some animals the organ
is supplied with fat, and in others it is devoid of it. The omentum
has both its starting-point and its attachment, with ambidental
vivipara, in the centre of the stomach, where the stomach has a kind
of suture; in non-ambidental vivipara it has its starting-point and
attachment in the chief of the ruminating stomachs.

15

The bladder also is of the nature of membrane, but of membrane
peculiar in kind, for it is extensile. The organ is not common to
all animals, but, while it is found in all the vivipara, the
tortoise is the only oviparous animal that is furnished therewithal.
The bladder, like ordinary membrane, if cut asunder will not grow
together again, unless the section be just at the commencement of
the urethra: except indeed in very rare cases, for instances of
healing have been known to occur. After death, the organ passes no
liquid excretion; but in life, in addition to the normal liquid
excretion, it passes at times dry excretion also, which turns into
stones in the case of sufferers from that malady. Indeed, instances
have been known of concretions in the bladder so shaped as closely
to resemble cockleshells.

Such are the properties, then, of vein, sinew and skin, of fibre
and membrane, of hair, nail, claw and hoof, of horns, of teeth, of
beak, of gristle, of bones, and of parts that are analogous to any
of the parts here enumerated.

16

Flesh, and that which is by nature akin to it in sanguineous
animals, is in all cases situated in between the skin and the bone, or
the substance analogous to bone; for just as spine is a counterpart of
bone, so is the flesh-like substance of animals that are constructed a
spinous system the counterpart of the flesh of animals constructed
on an osseous one.

Flesh can be divided asunder in any direction, not lengthwise only
as is the case with sinew and vein. When animals are subjected to
emaciation the flesh disappears, and the creatures become a mass of
veins and fibres; when they are over fed, fat takes the place of
flesh. Where the flesh is abundant in an animal, its veins are
somewhat small and the blood abnormally red; the viscera also and
the stomach are diminutive; whereas with animals whose veins are large
the blood is somewhat black, the viscera and the stomach are large,
and the flesh is somewhat scanty. And animals with small stomachs
are disposed to take on flesh.

17

Again, fat and suet differ from one another. Suet is frangible
in all directions and congeals if subjected to extreme cold, whereas
fat can melt but cannot freeze or congeal; and soups made of the flesh
of animals supplied with fat do not congeal or coagulate, as is
found with horse-flesh and pork; but soups made from the flesh of
animals supplied with suet do coagulate, as is seen with mutton and
goat's flesh. Further, fat and suet differ as to their localities: for
fat is found between the skin and flesh, but suet is found only at the
limit of the fleshy parts. Also, in animals supplied with fat the
omentum or caul is supplied with fat, and it is supplied with suet
in animals supplied with suet. Moreover, ambidental animals are
supplied with fat, and non-ambidentals with suet.

Of the viscera the liver in some animals becomes fatty, as,
among fishes, is the case with the selachia, by the melting of whose
livers an oil is manufactured. These cartilaginous fish themselves
have no free fat at all in connexion with the flesh or with the
stomach. The suet in fish is fatty, and does not solidify or
congeal. All animals are furnished with fat, either intermingled
with their flesh, or apart. Such as have no free or separate fat are
less fat than others in stomach and omentum, as the eel; for it has
only a scanty supply of suet about the omentum. Most animals take on
fat in the belly, especially such animals as are little in motion.

The brains of animals supplied with fat are oily, as in the pig;
of animals supplied with suet, parched and dry. But it is about the
kidneys more than any other viscera that animals are inclined to
take on fat; and the right kidney is always less supplied with fat
than the left kidney, and, be the two kidneys ever so fat, there is
always a space devoid of fat in between the two. Animals supplied with
suet are specially apt to have it about the kidneys, and especially
the sheep; for this animal is apt to die from its kidneys being
entirely enveloped. Fat or suet about the kidney is superinduced by
overfeeding, as is found at Leontini in Sicily; and consequently in
this district they defer driving out sheep to pasture until the day is
well on, with the view of limiting their food by curtailment of the
hours of pasture.

18

The part around the pupil of the eye is fatty in all animals,
and this part resembles suet in all animals that possess such a part
and that are not furnished with hard eyes.

Fat animals, whether male or female, are more or less unfitted for
breeding purposes. Animals are disposed to take on fat more when old
than when young, and especially when they have attained their full
breadth and their full length and are beginning to grow depthways.

19

And now to proceed to the consideration of the blood. In
sanguineous animals blood is the most universal and the most
indispensable part; and it is not an acquired or adventitious part,
but it is a consubstantial part of all animals that are not corrupt or
moribund. All blood is contained in a vascular system, to wit, the
veins, and is found nowhere else, excepting in the heart. Blood is not
sensitive to touch in any animal, any more than the excretions of
the stomach; and the case is similar with the brain and the marrow.
When flesh is lacerated, blood exudes, if the animal be alive and
unless the flesh be gangrened. Blood in a healthy condition is
naturally sweet to the taste, and red in colour, blood that
deteriorates from natural decay or from disease more or less black.
Blood at its best, before it undergoes deterioration from either
natural decay or from disease, is neither very thick nor very thin. In
the living animal it is always liquid and warm, but, on issuing from
the body, it coagulates in all cases except in the case of the deer,
the roe, and the like animals; for, as a general rule, blood
coagulates unless the fibres be extracted. Bull's blood is the
quickest to coagulate.

Animals that are internally and externally viviparous are more
abundantly supplied with blood than the sanguineous ovipara. Animals
that are in good condition, either from natural causes or from their
health having been attended to, have the blood neither too abundant-as
creatures just after drinking have the liquid inside them in
abundance-nor again very scanty, as is the case with animals when
exceedingly fat. For animals in this condition have pure blood, but
very little of it, and the fatter an animal gets the less becomes
its supply of blood; for whatsoever is fat is destitute of blood.

A fat substance is incorruptible, but blood and all things
containing it corrupt rapidly, and this property characterizes
especially all parts connected with the bones. Blood is finest and
purest in man; and thickest and blackest in the bull and the ass, of
all vivipara. In the lower and the higher parts of the body blood is
thicker and blacker than in the central parts.

Blood beats or palpitates in the veins of all animals alike all
over their bodies, and blood is the only liquid that permeates the
entire frames of living animals, without exception and at all times,
as long as life lasts. Blood is developed first of all in the heart of
animals before the body is differentiated as a whole. If blood be
removed or if it escape in any considerable quantity, animals fall
into a faint or swoon; if it be removed or if it escape in an
exceedingly large quantity they die. If the blood get exceedingly
liquid, animals fall sick; for the blood then turns into something
like ichor, or a liquid so thin that it at times has been known to
exude through the pores like sweat. In some cases blood, when
issuing from the veins, does not coagulate at all, or only here and
there. Whilst animals are sleeping the blood is less abundantly
supplied near the exterior surfaces, so that, if the sleeping creature
be pricked with a pin, the blood does not issue as copiously as it
would if the creature were awake. Blood is developed out of ichor by
coction, and fat in like manner out of blood. If the blood get
diseased, haemorrhoids may ensue in the nostril or at the anus, or the
veins may become varicose. Blood, if it corrupt in the body, has a
tendency to turn into pus, and pus may turn into a solid concretion.

Blood in the female differs from that in the male, for,
supposing the male and female to be on a par as regards age and
general health, the blood in the female is thicker and blacker than in
the male; and with the female there is a comparative superabundance of
it in the interior. Of all female animals the female in man is the
most richly supplied with blood, and of all female animals the
menstruous discharges are the most copious in woman. The blood of
these discharges under disease turns into flux. Apart from the
menstrual discharges, the female in the human species is less
subject to diseases of the blood than the male.

Women are seldom afflicted with varicose veins, with haemorrhoids,
or with bleeding at the nose, and, if any of these maladies supervene,
the menses are imperfectly discharged.

Blood differs in quantity and appearance according to age; in very
young animals it resembles ichor and is abundant, in the old it is
thick and black and scarce, and in middle-aged animals its qualities
are intermediate. In old animals the blood coagulates rapidly, even
blood at the surface of the body; but this is not the case with
young animals. Ichor is, in fact, nothing else but unconcocted
blood: either blood that has not yet been concocted, or that has
become fluid again.

20

We now proceed to discuss the properties of marrow; for this is
one of the liquids found in certain sanguineous animals. All the
natural liquids of the body are contained in vessels: as blood in
veins, marrow in bones other moistures in membranous structures of the
skin

In young animals the marrow is exceedingly sanguineous, but, as
animals grow old, it becomes fatty in animals supplied with fat, and
suet-like in animals with suet. All bones, however, are not supplied
with marrow, but only the hollow ones, and not all of these. For of
the bones in the lion some contain no marrow at all, and some are only
scantily supplied therewith; and that accounts, as was previously
observed, for the statement made by certain writers that the lion is
marrowless. In the bones of pigs it is found in small quantities;
and in the bones of certain animals of this species it is not found at
all.

These liquids, then, are nearly always congenital in animals,
but milk and sperm come at a later time. Of these latter, that
which, whensoever it is present, is secreted in all cases
ready-made, is the milk; sperm, on the other hand, is not secreted out
in all cases, but in some only, as in the case of what are
designated thori in fishes.

Whatever animals have milk, have it in their breasts. All
animals have breasts that are internally and externally viviparous, as
for instance all animals that have hair, as man and the horse; and the
cetaceans, as the dolphin, the porpoise, and the whale-for these
animals have breasts and are supplied with milk. Animals that are
oviparous or only externally viviparous have neither breasts nor milk,
as the fish and the bird.

All milk is composed of a watery serum called 'whey', and a
consistent substance called curd (or cheese); and the thicker the
milk, the more abundant the curd. The milk, then, of non-ambidentals
coagulates, and that is why cheese is made of the milk of such animals
under domestication; but the milk of ambidentals does not coagulate,
nor their fat either, and the milk is thin and sweet. Now the
camel's milk is the thinnest, and that of the human species next after
it, and that of the ass next again, but cow's milk is the thickest.
Milk does not coagulate under the influence of cold, but rather runs
to whey; but under the influence of heat it coagulates and thickens.
As a general rule milk only comes to animals in pregnancy. When the
animal is pregnant milk is found, but for a while it is unfit for use,
and then after an interval of usefulness it becomes unfit for use
again. In the case of female animals not pregnant a small quantity
of milk has been procured by the employment of special food, and cases
have been actually known where women advanced in years on being
submitted to the process of milking have produced milk, and in some
cases have produced it in sufficient quantities to enable them to
suckle an infant.

The people that live on and about Mount Oeta take such she-goats
as decline the male and rub their udders hard with nettles to cause an
irritation amounting to pain; hereupon they milk the animals,
procuring at first a liquid resembling blood, then a liquid mixed with
purulent matter, and eventually milk, as freely as from females
submitting to the male.

As a general rule, milk is not found in the male of man or of
any other animal, though from time to time it has been found in a
male; for instance, once in Lemnos a he-goat was milked by its dugs
(for it has, by the way, two dugs close to the penis), and was
milked to such effect that cheese was made of the produce, and the
same phenomenon was repeated in a male of its own begetting. Such
occurrences, however, are regarded as supernatural and fraught with
omen as to futurity, and in point of fact when the Lemnian owner of
the animal inquired of the oracle, the god informed him that the
portent foreshadowed the acquisition of a fortune. With some men,
after puberty, milk can be produced by squeezing the breasts; cases
have been known where on their being subjected to a prolonged
milking process a considerable quantity of milk has been educed.

In milk there is a fatty element, which in clotted milk gets to
resemble oil. Goat's milk is mixed with sheep's milk in Sicily, and
wherever sheep's milk is abundant. The best milk for clotting is not
only that where the cheese is most abundant, but that also where the
cheese is driest.

Now some animals produce not only enough milk to rear their young,
but a superfluous amount for general use, for cheese-making and for
storage. This is especially the case with the sheep and the goat,
and next in degree with the cow. Mare's milk, by the way, and milk
of the she-ass are mixed in with Phrygian cheese. And there is more
cheese in cow's milk than in goat's milk; for graziers tell us that
from nine gallons of goat's milk they can get nineteen cheeses at an
obol apiece, and from the same amount of cow's milk, thirty. Other
animals give only enough of milk to rear their young withal, and no
superfluous amount and none fitted for cheese-making, as is the case
with all animals that have more than two breasts or dugs; for with
none of such animals is milk produced in superabundance or used for
the manufacture of cheese.

The juice of the fig and rennet are employed to curdle milk. The
fig-juice is first squeezed out into wool; the wool is then washed and
rinsed, and the rinsing put into a little milk, and if this be mixed
with other milk it curdles Rennet is a kind of milk, for it is found
in the stomach of the animal while it is yet suckling.

21

Rennet then consists of milk with an admixture of fire, which
comes from the natural heat of the animal, as the milk is concocted.
All ruminating animals produce rennet, and, of ambidentals, the
hare. Rennet improves in quality the longer it is kept; and cow's
rennet, after being kept a good while, and also hare's rennet, is good
for diarrhoea, and the best of all rennet is that of the young deer.

In milk-producing animals the comparative amount of the yield
varies with the size of the animal and the diversities of pasturage.
For instance, there are in Phasis small cattle that in all cases
give a copious supply of milk, and the large cows in Epirus yield each
one daily some nine gallons of milk, and half of this from each pair
of teats, and the milker has to stand erect, stooping forward a
little, as otherwise, if he were seated, he would be unable to reach
up to the teats. But, with the exception of the ass, all the
quadrupeds in Epirus are of large size, and relatively, the cattle and
the dogs are the largest. Now large animals require abundant
pasture, and this country supplies just such pasturage, and also
supplies diverse pasture grounds to suit the diverse seasons of the
year. The cattle are particularly large, and likewise the sheep of the
so-called Pyrrhic breed, the name being given in honour of King
Pyrrhus.

Some pasture quenches milk, as Median grass or lucerne, and that
especially in ruminants; other feeding renders it copious, as
cytisus and vetch; only, by the way, cytisus in flower is not
recommended, as it has burning properties, and vetch is not good for
pregnant kine, as it causes increased difficulty in parturition.
However, beasts that have access to good feeding, as they are
benefited thereby in regard to pregnancy, so also being well nourished
produce milk in plenty. Some of the leguminous plants bring milk in
abundance, as for instance, a large feed of beans with the ewe, the
common she-goat, the cow, and the small she-goat; for this feeding
makes them drop their udders. And, by the way, the pointing of the
udder to the ground before parturition is a sign of there being plenty
of milk coming.

Milk remains for a long time in the female, if she be kept from
the male and be properly fed, and, of quadrupeds, this is especially
true of the ewe; for the ewe can be milked for eight months. As a
general rule, ruminating animals give milk in abundance, and milk
fitted for cheese manufacture. In the neighbourhood of Torone cows run
dry for a few days before calving, and have milk all the rest of the
time. In women, milk of a livid colour is better than white for
nursing purposes; and swarthy women give healthier milk than fair
ones. Milk that is richest in cheese is the most nutritious, but
milk with a scanty supply of cheese is the more wholesome for
children.

22

All sanguineous animals eject sperm. As to what, and how, it
contributes to generation, these questions will be discussed in
another treatise. Taking the size of his body into account, man
emits more sperm than any other animal. In hairy-coated animals the
sperm is sticky, but in other animals it is not so. It is white in all
cases, and Herodotus is under a misapprehension when he states that
the Aethiopians eject black sperm.

Sperm issues from the body white and consistent, if it be healthy,
and after quitting the body becomes thin and black. In frosty
weather it does not coagulate, but gets exceedingly thin and watery
both in colour and consistency; but it coagulates and thickens under
the influence of heat. If it be long in the womb before issuing out,
it comes more than usually thick; and sometimes it comes out dry and
compact. Sperm capable of impregnating or of fructification sinks in
water; sperm incapable Of producing that result dissolves away. But
there is no truth in what Ctesias has written about the sperm of the
elephant.

Book IV

1

We have now treated, in regard to blooded animals of the parts
they have in common and of the parts peculiar to this genus or that,
and of the parts both composite and simple, whether without or within.
We now proceed to treat of animals devoid of blood. These animals
are divided into several genera.

One genus consists of so-called 'molluscs'; and by the term
'mollusc' we mean an animal that, being devoid of blood, has its
flesh-like substance outside, and any hard structure it may happen
to have, inside-in this respect resembling the red-blooded animals,
such as the genus of the cuttle-fish.

Another genus is that of the malacostraca. These are animals
that have their hard structure outside, and their soft or fleshlike
substance inside, and the hard substance belonging to them has to be
crushed rather than shattered; and to this genus belongs the
crawfish and the crab.

A third genus is that of the ostracoderms or 'testaceans'. These
are animals that have their hard substance outside and their
flesh-like substance within, and their hard substance can be shattered
but not crushed; and to this genus belong the snail and the oyster.

The fourth genus is that of insects; and this genus comprehends
numerous and dissimilar species. Insects are creatures that, as the
name implies, have nicks either on the belly or on the back, or on
both belly and back, and have no one part distinctly osseous and no
one part distinctly fleshy, but are throughout a something
intermediate between bone and flesh; that is to say, their body is
hard all through, inside and outside. Some insects are wingless,
such as the iulus and the centipede; some are winged, as the bee,
the cockchafer, and the wasp; and the same kind is in some cases
both winged and wingless, as the ant and the glow-worm.

In molluscs the external parts are as follows: in the first place,
the so-called feet; secondly, and attached to these, the head;
thirdly, the mantle-sac, containing the internal parts, and
incorrectly designated by some writers the head; and, fourthly, fins
round about the sac. (See diagram. ) In all molluscs the head is found
to be between the feet and the belly. All molluscs are furnished with
eight feet, and in all cases these feet are severally furnished with
a double row of suckers, with the exception of one single species of
poulpe or octopus. The sepia, the small calamary and the large
calamary have an exceptional organ in a pair of long arms or
tentacles, having at their extremities a portion rendered rough by
the presence of two rows of suckers; and with these arms or tentacles
they apprehend their food and draw it into their mouths, and in
stormy weather they cling by them to a rock and sway about in the
rough water like ships lying at anchor. They swim by the aid of the
fins that they have about the sac. In all cases their feet are
furnished with suckers.

The octopus, by the way, uses his feelers either as feet or hands;
with the two which stand over his mouth he draws in food, and the last
of his feelers he employs in the act of copulation; and this last one,
by the way, is extremely sharp, is exceptional as being of a whitish
colour, and at its extremity is bifurcate; that is to say, it has an
additional something on the rachis, and by rachis is meant the
smooth surface or edge of the arm on the far side from the suckers.
(See diagram. )

In front of the sac and over the feelers they have a hollow
tube, by means of which they discharge any sea-water that they may
have taken into the sac of the body in the act of receiving food by
the mouth. They can shift the tube from side to side, and by means
of it they discharge the black liquid peculiar to the animal.

Stretching out its feet, it swims obliquely in the direction of
the so-called head, and by this mode of swimming it can see in
front, for its eyes are at the top, and in this attitude it has its
mouth at the rear. The 'head', while the creature is alive, is hard,
and looks as though it were inflated. It apprehends and retains
objects by means of the under-surface of its arms, and the membrane in
between its feet is kept at full tension; if the animal get on to
the sand it can no longer retain its hold.

There is a difference between the octopus and the other molluscs
above mentioned: the body of the octopus is small, and his feet are
long, whereas in the others the body is large and the feet short; so
short, in fact, that they cannot walk on them. Compared with one
another, the teuthis, or calamary, is long-shaped, and the sepia
flat-shaped; and of the calamaries the so-called teuthus is much
bigger than the teuthis; for teuthi have been found as much as five
ells long. Some sepiae attain a length of two ells, and the feelers of
the octopus are sometimes as long, or even longer. The species teuthus
is not a numerous one; the teuthus differs from the teuthis in
shape; that is, the sharp extremity of the teuthus is broader than
that of the other, and, further, the encircling fin goes all round the
trunk, whereas it is in part lacking in the teuthis; both animals
are pelagic.

In all cases the head comes after the feet, in the middle of the
feet that are called arms or feelers. There is here situated a
mouth, and two teeth in the mouth; and above these two large eyes, and
betwixt the eyes a small cartilage enclosing a small brain; and within
the mouth it has a minute organ of a fleshy nature, and this it uses
as a tongue, for no other tongue does it possess. Next after this,
on the outside, is what looks like a sac; the flesh of which it is
made is divisible, not in long straight strips, but in annular flakes;
and all molluscs have a cuticle around this flesh. Next after or at
the back of the mouth comes a long and narrow oesophagus, and close
after that a crop or craw, large and spherical, like that of a bird;
then comes the stomach, like the fourth stomach in ruminants; and
the shape of it resembles the spiral convolution in the trumpet-shell;
from the stomach there goes back again, in the direction of the mouth,
thin gut, and the gut is thicker than the oesophagus. (See diagram. )

Molluscs have no viscera, but they have what is called a
mytis, and on it a vessel containing a thick black juice; in the sepia
or cuttle-fish this vessel is the largest, and this juice is most
abundant. All molluscs, when frightened, discharge such a juice, but
the discharge is most copious in the cuttle-fish. The mytis, then,
is situated under the mouth, and the oesophagus runs through it; and
down below at the point to which the gut extends is the vesicle of the
black juice, and the animal has the vesicle and the gut enveloped in
one and the same membrane, and by the same membrane, same orifice
discharges both the black juice and the residuum. The animals have
also certain hair-like or furry growths in their bodies.

In the sepia, the teuthis, and the teuthus the hard parts are
within, towards the back of the body; those parts are called in one
the sepium, and in the other the 'sword'. They differ from one
another, for the sepium in the cuttle-fish and teuthus is hard and
flat, being a substance intermediate between bone and fishbone, with
(in part) a crumbling, spongy texture, but in the teuthis the part
is thin and somewhat gristly. These parts differ from one another in
shape, as do also the bodies of the animals. The octopus has nothing
hard of this kind in its interior, but it has a gristly substance
round the head, which, if the animal grows old, becomes hard.

The females differ from the males. The males have a duct in
under the oesophagus, extending from the mantle-cavity to the lower
portion of the sac, and there is an organ to which it attaches,
resembling a breast; (see diagram) in the female there are two of
these organs, situated higher up; (see diagram) with both sexes there
are underneath these organs certain red formations. The egg of the
octopus is single, uneven on its surface, and of large size; the
fluid substance within is all uniform in colour, smooth, and in
colour white; the size of the egg is so great as to fill a vessel
larger than the creature's head. The sepia has two sacs, and inside
them a number of eggs, like in appearance to white hailstones. For
the disposition of these parts I must refer to my anatomical
diagrams.

The males of all these animals differ from the females, and the
difference between the sexes is most marked in the sepia; for the back
of the trunk, which is blacker than the belly, is rougher in the
male than in the female, and in the male the back is striped, and
the rump is more sharply pointed.