BOOK THE EIGHTH.

CHAPTER I.

1. THE nature of animals and their mode of reproduction has now been described. Their actions and mode of life also differ according to their disposition and their food. For almost all animals present traces of their moral dispositions, though these distinctions are most remarkable in man. For most of them, as we remarked, when speaking of their various parts, appear to exhibit gentleness or ferocity, mildness or cruelty, courage or cowardice, fear or boldness, violence or cunning; and many of them exhibit something like a rational consciousness, as we remarked in speaking of their parts. For they differ from man, and man from the other animals, in a greater or less degree; for some of these traits are exhibited strongly in man, and others in other animals.

2. Others differ in proportion. For as men exhibit art, wisdom, and intelligence, animals possess, by way of compensation, some other physical power. This is most conspicuous in the examination of infants, for in them we see, as were, the vestiges and seeds of their future disposition; nor does their soul at this period differ in any respect from that of an animal; so that it is not unreasonable for animals to present the same, or similar, or analogous appearances. Nature passes so gradually from inanimate to animate things, that from their continuity their boundary and the mean between them is indistinct. The race of plants succeeds immediately that of inanimate objects; and these differ from each other in the proportion of life in which they participate; for, compared with other bodies, plants appear to possess life, though, when compared with animals, they appear inanimate.

3. The change from plants to animals, however, is gradual, as I before observed For a person might question to

which of these classes some marine objects belong; for many of them are attached to the rock, and perish as soon as they are separated from it. The pinnæ are attached to the rocks, the solens cannot live after they are taken away from their localities; and, on the whole, all the testacea resemble plants, if we compare them with locomotive animals. Some of them appear to have no sensation; in others it is very dull. The body of some of them is naturally fleshy, as of those which are called tethya; and the acalephe and the sponge entirely resemble plants; the progress is always gradual by which one appears to have more life and motion than another.

4. In the vital actions also we may observe the same manner. For vegetables which are produced from seed appear to have no other work beyond reproduction; nor do some animals appear to have any other object in their existence. This object then is common to them all; but as sensation advances, their manner of life differs in their having pleasure in sexual intercourse, in their mode of parturition and rearing their young. Some of them, like plants, simply accomplish their peculiar mode of reproduction at an appointed season, and others are diligent in rearing their young; but as soon as this is accomplished they separate from them, and have no farther communication; but those that are more intelligent, and possess more memory, use their offspring in a more civilized manner.

5. The work of reproduction is one part of their life, the work of procuring food forms another. These two occupy their labour and their life. Their food differs in the substances of which it consists, and all the natural increase of the body is derived from food. That which is natural is pleasant, and all animals follow that which is pleasant to their nature.

CHAPTER II.

1. ANIMALS are divided according to the localities which they inhabit; for some animals are terrestrial, others are aquatic. They also admit of a ternary division, those that breathe air and those that breathe water, one of these classes is terrestrial, the other is aquatic; the third class does not breathe either air or water, but they are adapted by nature to receive refreshment from each of these elements; and some of these are called terrestrial, others are aquatic, though they

neither breathe air or water; and there are other animals which procure their food and make their abode in either of these elements. For many that breathe air, and produce their young upon the land, procure their food from the water, where they generally make their abode; and these are the only animals which appear to be doubtful, for they may be arranged either as terrestrial or aquatic animals.

2. Of those that breathe water, none have feet or wings, nor seek their food on land; but many of those that are terrestrial, and breathe air, do so ; some of them so much so, that they cannot live when separated from the water, as those which are called marine turtles, and crocodiles, and hippopotami, and seals, and some of the smaller creatures, as the water tortoise and the frog tribe; for all these are suffocated if their respiration is suspended for any length of time. They produce their young and rear them on dry land; others do so near the dry land, while they reside in the water.

3. Of all animals the most remarkable in this particular is the dolphin, and some other aquatic animals and cetacea which are of this habit, as the whale and others which have a blowhole; for it is not easy to arrange them either with aquatic or terrestrial animals, if we consider animals that breathe air as terrestrial, and those that breathe water as aquatics, for they partake of the characters of both classes; for they receive the sea and eject it through their blowhole, and air through their lungs, for they have this part, and breathe through it. And the dolphin, when captured in nets, is often suffocated, from the impossibility of breathing. It will live for a long while out of water, snoring and groaning like other breathing animals. It sleeps with its snout above the water, in order that it may breathe through it.

4. It is thus impossible to arrange it under both of these contrary divisions, but it would appear that the aquatic animals must be further subdivided; for they breathe and eject water for the same reason as others breathe air, for the sake of coolness. Other animals do this for the sake of food; for those animals which obtain their food in the water, must also, at the same time, swallow some of the fluid, and have an organ by which they can eject it. Those creatures which use water instead of air for breathing have gills; those that use it for food have a blowhole. These

creatures are sanguineous. The nature of the malacia and malacostraca is the same; for these swallow water for food.

5. Those animals which breathe air, but live in the water, and those which breathe water, and have gills, but go out upon dry land and take their food there, belong to two divisions of aquatic animals. This last division is represented by a single animal called the cordylus (water newt); for this animal has no lungs, but gills; and it goes on dry land to procure its food. It has four feet, so that it appears natural that it should walk. In all these animals nature appears to be, as it were, turned aside, and some of the males appear to be females, and the females have a male appearance; for animals which have but small diversity in particular parts, exhibit great variations in the whole body.

6. This is evident in castrated animals; for if a small portion only of the body is destroyed, the animal becomes a female; so that it is plain that if a very minute portion in the original composition of an animal becomes changed, if that portion belongs to the origin of the species, it might become either male or female; or, if taken away altogether, the animal might be neuter. And so, either way, it might become a land or aquatic animal, if only a small change took place. it happens that some become terrestrial and others aquatic animals, and some are not amphibious which others are, because in their original generation they received some kind of substance which they use for food. For that which is natural is agreeable to every animal, as I have said before.

CHAPTER III.

1. WHEN animals are divided in three ways into aquatic and land animals, because they either breathe air or water, or from the composition of their bodies; or, in the third place, from their food, their manner of life will be found to agree with these divisions. For some follow both the composition of their bodies and the nature of their food, and their respiration of either water or air. Others only agree with their composition and food.

2. The testacea which are immoveable live by a fluid which percolates through the dense parts of the sea, and

being digested because it is lighter than the sea water, thus returns to its original nature. That this fluid exists in the sea, and is capable of infiltration is manifest, and may be proved by experiment; for if anyone will make a thin waxen vessel, and sink it empty in the sea, in a night and a day, it may be taken up full of water, which is drinkable.

3. The acalephe (actinia) feeds upon any small fish which may fall in its way. Its mouth is placed in the centre of its body. This organ is conspicuous in the larger individuals: like the oyster, it has a passage for the exclusion of its food, which is placed above. The acalephe appears to resemble the internal part of the oyster, and it makes use of the rock, as the oyster does of its shell. (The patella also is free, and wanders about in search of food.)

4. Among the locomotive testacea, some are carnivorous, and live on small fish, as the purpura, for this creature is carnivorous, it is therefore caught with a bait of flesh: others live upon marine plants. The marine turtles live upon shell-fish, for which purpose they have a very powerful mouth; for if any of them take a stone or anything else, they break and eat it. This animal leaves the water and eats grass. They often suffer and perish, when they are dried up as they float on the surface, for they are not able to dive readily.

5. The malacostraca are of the same nature, for they eat everything; they feed upon stones and mud, seaweeds and dung, as the rock crabs, and are also carnivorous. The spiny lobsters also overcome large fishes, and a kind of retribution awaits them in turn, for the polypus prevails over the lobster, for they are not inconvenienced by the shell of the lobster, so that if the lobsters perceive them in the same net with them, they die from fear. The spiny lobsters overcome the congers, for their roughness prevents them from falling off. The congers devour the polypi which cannot adhere to them on account of the smoothness of their surface; all the malacia are carnivorous.

6. The spiny lobsters also live on small fish, which they hunt for in their holes, for they are produced in such parts of the sea as are rough and stony, and in those places make their habitations; whatever they capture, they bring to their mouth