Crabs

copulate at the front parts of one another, belly to
belly, throwing their overlapping opercula to meet one another:
first the smaller crab mounts the larger at the rear; after he has
mounted, the larger one turns on one side. Now, the female differs
in no respect from the male except in the circumstance that its
operculum is larger, more elevated, and more hairy, and into this
operculum it spawns its eggs and in the same neighbourhood is the
outlet of the residuum. In the copulative process of these animals
there is no protrusion of a member from one animal into the other.

Crustaceans copulate,

as the crawfish, the lobster, the carid
and the like, just like the opisthuretic quadrupeds, when the one
animal turns up its tail and the other puts his tail on the other's
tail. Copulation takes place in the early spring, near to the shore;
and, in fact, the process has often been observed in the case of all
these animals. Sometimes it takes place about the time when the figs
begin to ripen. Lobsters and carids copulate in like manner.

Now cuttle-fish

and calamaries swim about closely intertwined,
with mouths and tentacles facing one another and fitting closely
together, and swim thus in opposite directions; and they fit their
so-called nostrils into one another, and the one sex swims backwards
and the other frontwards during the operation. And the female lays its
spawn by the so-called 'blow-hole'; and, by the way, some declare that
it is at this organ that the coition really takes place.

Molluscs,

such as the octopus, the sepia, and the calamary, have
sexual intercourse all in the same way; that is to say, they unite
at the mouth, by an interlacing of their tentacles. When, then, the
octopus rests its so-called head against the ground and spreads abroad
its tentacles, the other sex fits into the outspreading of these
tentacles, and the two sexes then bring their suckers into mutual
connexion.

Some assert that the male has a kind of penis in one of his
tentacles, the one in which are the largest suckers; and they
further assert that the organ is tendinous in character, growing
attached right up to the middle of the tentacle, and that the latter
enables it to enter the nostril or funnel of the female.

The repeated

observation of this phenomenon has led to the
notion that the process was equivalent to coition, but the fact is
that a similar phenomenon is observable in quadrupeds. For at the
rutting seasons both the males and the females take to running at
their genitals, and the two sexes take to smelling each other at those
parts. (With partridges, by the way, if the female gets to leeward
of the male, she becomes thereby impregnated. And often when they
happen to be in heat she is affected in this wise by the voice of
the male, or by his breathing down on her as he flies overhead; and,
by the way, both the male and the female partridge keep the mouth wide
open and protrude the tongue in the process of coition.)

The actual process of copulation on the part of oviparous fishes
is seldom accurately observed, owing to the fact that they very soon
fall aside and slip asunder. But, for all that, the process has been
observed to take place in the manner above described.

In the case of oviparous fishes the process of coition is less
open to observation. In point of fact, some are led by the want of
actual observation to surmise that the female becomes impregnated by
swallowing the seminal fluid of the male. And there can be no doubt
that this proceeding on the part of the female is often witnessed; for
at the rutting season the females follow the males and perform this
operation, and strike the males with their mouths under the belly, and
the males are thereby induced to part with the sperm sooner and more
plentifully. And, further, at the spawning season the males go in
pursuit of the females, and, as the female spawns, the males swallow
the eggs; and the species is continued in existence by the spawn
that survives this process. On the coast of Phoenicia they take
advantage of these instinctive propensities of the two sexes to
catch both one and the other: that is to say, by using the male of the
grey mullet as a decoy they collect and net the female, and by using
the female, the male.

In viviparous animals furnished with feet there is outwardly one
and the same duct for the sperm and the liquid residuum; but there are
separate ducts internally, as has been observed in the differentiation
of the organs. And with such animals as are not viviparous the same
passage serves for the discharge also of the solid residuum; although,
internally, there are two passages, separate but near to one
another. And these remarks apply to both male and female; for these
animals are unprovided with a bladder except in the case of the
tortoise; and the she-tortoise, though furnished with a bladder, has
only one passage; and tortoises, by the way, belong to the ovipara.

Now neither fishes nor any animals devoid of feet are
furnished with testicles, but male serpents and male fishes have a
pair of ducts which fill with milt or sperm at the rutting season, and
discharge, in all cases, a milk-like juice. These ducts unite, as in
birds; for birds, by the way, have their testicles in their
interior, and so have all ovipara that are furnished with feet. And
this union of the ducts is so far continued and of such extension as
to enter the receptive organ in the female.

It is the same

with the dolphin and with all cetaceans; that
is to say, they come side by side, male and female, and copulate,
and the act extends over a time which is neither short nor very long.

Again, in cartilaginous fishes the male, in some species,
differs from the female in the fact that he is furnished with two
appendages hanging down from about the exit of the residuum, and
that the female is not so furnished; and this distinction between
the sexes is observed in all the species of the sharks and dog-fish.

fish

All fishes, with the exception of the flat selachians, lie down
side by side, and copulate belly to belly. Fishes, however, that are
flat and furnished with tails-as the ray, the trygon, and the
like-copulate not only in this way, but also, where the tail from
its thinness is no impediment, by mounting of the male upon the
female, belly to back. But the rhina or angel-fish, and other like
fishes where the tail is large, copulate only by rubbing against one
another sideways, belly to belly. Some men assure us that they have
seen some of the selachia copulating hindways, dog and bitch. In the
cartilaginous species the female is larger than the male; and the same
is the case with other fishes for the most part. And among
cartilaginous fishes are included, besides those already named, the
bos, the lamia, the aetos, the narce or torpedo, the fishing-frog, and
all the galeodes or sharks and dogfish. Cartilaginous fishes, then, of
all kinds, have in many instances been observed copulating in the
way above mentioned; for, by the way, in viviparous animals the
process of copulation is of longer duration than in the ovipara.

Oviparous

quadrupeds cover one another in the same way. That is to
say, in some cases the male mounts the female precisely as in the
viviparous animals, as is observed in both the land and the sea
tortoise....And these creatures have an organ in which the ducts
converge, and with which they perform the act of copulation, as is
also observed in the toad, the frog, and all other animals of the same
group.
Long animals devoid of feet, like serpents and muraenae,
intertwine in coition, belly to belly. And, in fact, serpents coil
round one another so tightly as to present the appearance of a
single serpent with a pair of heads. The same mode is followed by
the saurians; that is to say, they coil round one another in the act
of coition.

Camels copulate

with the female in
a sitting posture, and the male straddles over and covers her, not
with the hinder presentment on the female's part but like the other
quadrupeds mentioned above, and they pass the whole day long in the
operation; when thus engaged they retire to lonely spots, and none but
their keeper dare approach them. And, be it observed, the penis of the
camel is so sinewy that bow-strings are manufactured out of it.
Elephants, also, copulate in lonely places, and especially by
river-sides in their usual haunts; the female squats down, and
straddles with her legs, and the male mounts and covers her. The
seal covers like all opisthuretic animals, and in this species the
copulation extends over a lengthened time, as is the case with the dog
and bitch; and the penis in the male seal is exceptionally large.

With regard

to large-sized vivipara, the hind only very rarely
sustains the mounting of the stag to the full conclusion of the
operation, and the same is the case with the cow as regards the
bull, owing to the rigidity of the penis of the bull. In point of
fact, the females of these animals elicit the sperm of the male in the
act of withdrawing from underneath him; and, by the way, this
phenomenon has been observed in the case of the stag and hind,
domesticated, of course. Covering with the wolf is the same as with
the dog. Cats do not copulate with a rearward presentment on the
part of the female, but the male stands erect and the female puts
herself underneath him; and, by the way, the female cat is
peculiarly lecherous, and wheedles the male on to sexual commerce, and
caterwauls during the operation.

The case

is similar in most other such animals; that is to say,
the majority of quadrupeds copulate as best they can, the male
mounting the female; and this is the only method of copulating adopted
by birds, though there are certain diversities of method observed even
in birds. For in some cases the female squats on the ground and the
male mounts on top of her, as is the case with the cock and hen
bustard, and the barn-door cock and hen; in other cases, the male
mounts without the female squatting, as with the male and female
crane; for, with these birds, the male mounts on to the back of the
female and covers her, and like the cock-sparrow consumes but very
little time in the operation. Of quadrupeds, bears perform the
operation lying prone on one another, in the same way as other
quadrupeds do while standing up; that is to say, with the belly of the
male pressed to the back of the female. Hedgehogs copulate erect,
belly to belly.

First,

then, we must proceed to treat of 'covering' in regard to
such animals as cover and are covered; and then after this to treat in
due order of other matters, both the exceptional and those of
general occurrence.

Those animals, then, cover and are covered in which there is a
duality of sex, and the modes of covering in such animals are not in
all cases similar nor analogous. For the red-blooded animals that
are viviparous and furnished with feet have in all cases organs
adapted for procreation, but the sexes do not in all cases come
together in like manner. Thus, opisthuretic animals copulate with a
rearward presentment, as is the case with the lion, the hare, and
the lynx; though, by the way, in the case of the hare, the female is
often observed to cover the male.

only that in

certain of these cases development is spontaneous, and in others is
not independent of the male; and the method of proceeding in regard to
these matters will set forth by and by, for the method is somewhat
like to the method followed in the case of birds. But whensoever
creatures are spontaneously generated, either in other animals, in the
soil, or on plants, or in the parts of these, and when such are
generated male and female, then from the copulation of such
spontaneously generated males and females there is generated a
something-a something never identical in shape with the parents, but a
something imperfect. For instance, the issue of copulation in lice
is nits; in flies, grubs; in fleas, grubs egg-like in shape; and
from these issues the parent-species is never reproduced, nor is any
animal produced at all, but the like nondescripts only.

In animals

where generation goes by heredity, wherever there is
duality of sex generation is due to copulation. In the group of
fishes, however, there are some that are neither male nor female,
and these, while they are identical generically with other fish,
differ from them specifically; but there are others that stand
altogether isolated and apart by themselves. Other fishes there are
that are always female and never male, and from them are conceived
what correspond to the wind-eggs in birds. Such eggs, by the way, in
birds are all unfruitful; but it is their nature to be independently
capable of generation up to the egg-stage, unless indeed there be some
other mode than the one familiar to us of intercourse with the male;
but concerning these topics we shall treat more precisely later on. In
the case of certain fishes, however, after they have spontaneously
generated eggs, these eggs develop into living animals;

Now there

is one property that animals are found to have in common
with plants. For some plants are generated from the seed of plants,
whilst other plants are self-generated through the formation of some
elemental principle similar to a seed; and of these latter plants some
derive their nutriment from the ground, whilst others grow inside
other plants, as is mentioned, by the way, in my treatise on Botany.
So with animals, some spring from parent animals according to their
kind, whilst others grow spontaneously and not from kindred stock; and
of these instances of spontaneous generation some come from putrefying
earth or vegetable matter, as is the case with a number of insects,
while others are spontaneously generated in the inside of animals
out of the secretions of their several organs.

As to the parts

internal and external that all animals are
furnished withal, and further as to the senses, to voice, and sleep,
and the duality sex, all these topics have now been touched upon. It
now remains for us to discuss, duly and in order, their several
modes of propagation.

These modes are many and diverse, and in some respects are like,
and in other respects are unlike to one another. As we carried on
our previous discussion genus by genus, so we must attempt to follow
the same divisions in our present argument; only that whereas in the
former case we started with a consideration of the parts of man, in
the present case it behoves us to treat of man last of all because
he involves most discussion. We shall commence, then, with testaceans,
and then proceed to crustaceans, and then to the other genera in due
order; and these other genera are, severally, molluscs, and insects,
then fishes viviparous and fishes oviparous, and next birds; and
afterwards we shall treat of animals provided with feet, both such
as are oviparous and such as are viviparous, and we may observe that
some quadrupeds are viviparous, but that the only viviparous biped
is man.

The fact

that the female is longer-lived than the
male is inferred from the fact that female fishes are caught older
than males. Furthermore, in all animals the upper and front parts
are better, stronger, and more thoroughly equipped in the male than in
the female, whereas in the female those parts are the better that
may be termed hinder-parts or underparts. And this statement is
applicable to man and to all vivipara that have feet. Again, the
female is less muscular and less compactly jointed, and more thin
and delicate in the hair-that is, where hair is found; and, where
there is no hair, less strongly furnished in some analogous substance.
And the female is more flaccid in texture of flesh, and more
knock-kneed, and the shin-bones are thinner; and the feet are more
arched and hollow in such animals as are furnished with feet. And with
regard to voice, the female in all animals that are vocal has a
thinner and sharper voice than the male; except, by the way, with
kine, for the lowing and bellowing of the cow has a deeper note than
that of the bull. With regard to organs of defence and offence, such
as teeth, tusks, horns, spurs, and the like, these in some species the
male possesses and the female does not; as, for instance, the hind has
no horns, and where the cock-bird has a spur the hen is entirely
destitute of the organ; and in like manner the sow is devoid of tusks.
In other species such organs are found in both sexes, but are more
perfectly developed in the male; as, for instance, the horn of the
bull is more powerful than the horn of the cow.

As a general rule,

in red-blooded animals furnished with feet
and not oviparous, the male is larger and longer-lived than the female
(except with the mule, where the female is longer-lived and bigger
than the male); whereas in oviparous and vermiparous creatures, as
in fishes and in insects, the female is larger than the male; as,
for instance, with the serpent, the phalangium or venom-spider, the
gecko, and the frog. The same difference in size of the sexes is found
in fishes, as, for instance, in the smaller cartilaginous fishes, in
the greater part of the gregarious species, and in all that live in
and about rocks.