1. The remaining class of sanguineous animals is that of serpents; these partake of both characters. The greater portion of them inhabit the land, a few inhabiting water are found in rivers. There are also serpents in the sea very like those on land, except in their head, which is more like that of the conger. There are many genera of sea-serpents, and they are of all kinds of colours; they do not exist in the deepest part of the ocean. Serpents are apodal, like fishes.
2. There are also marine scolopendræ,[56] very like those on land, but rather less; they live in rocky places; in colour they are redder, and they have more feet, and slighter legs than in the terrestrial species. These also, like the serpents, are not found in deep places.
3. And there is a small fish which lives among the rocks, which some call echineis;[57] some people use it for trials and philtres; it is not fit for food. Some people say it has feet, but it has none; the fins, however, are like feet, which gives it this appearance. I have now described the external parts of sanguineous animals, their nature, and their number, and the differences which occur amongst them.
Chapter XI.
1. First of all we will speak of the internal parts of sanguineous animals, for the greatest number of genera differ from other animals, some being sanguineous, others ex-sanguineous. The sanguineous genera are man, viviparous and oviparous quadrupeds, birds, fishes, and whales, and perhaps others that are anonymous, because they do not form a genus, but simply species amongst each other, as the serpent and the crocodile.
2. All viviparous quadrupeds have an œsophagus and trachea, situated as in man, and so have oviparous quadrupeds and birds, though there is some difference in the formation of these parts; all that breathe by inhaling and exhaling air have lungs, trachea, and œsophagus. The position of the œsophagus and trachea, though similar, is not the same, nor are the lungs alike in all, nor similar in position.
3. All sanguineous animals have a heart, and a division in the middle of the body, called a diaphragm. In small animals its smallness and thinness render it less apparent. The heart of the ox is peculiar; for there is a kind of ox, though not the whole genus, which has a bone in its heart, and there is also a bone in the heart of the horse.
4. Not all animals have lungs, fish and those with gills have no lungs. All sanguineous animals have a liver, generally a spleen also; but in oviparous animals that are not viviparous, the spleen is so small as nearly to escape notice, as in most birds, the pigeon, kite,[58] hawk,[59] and owl. The ægocephalus[60] has none at all. Oviparous quadrupeds are of the same nature, for they have a very small spleen, as the tortoise, emys,[61] phryne, lizard, crocodile, and frog.
5. Some animals have a gall upon the liver, others none. Among viviparous quadrupeds the stag[62] has none, nor the deer,[63] horse, mule, ass, seal, and some swine. The Achaïnian stag appears to have the gall in the tail; that which they call gall in these animals resembles it in colour, but it is not liquid like gall, but more like the spleen in its internal structure.
6. All, while they are alive, have worms[64] in the head; they are produced in the hollow part under the hypoglottis, and near the vertebræ, where the head is joined on. In size they resemble very large maggots; they are numerous, and continuous, in number not generally more than twenty. Stags, as I have observed, have no gall, but their intestines are so bitter that dogs will not eat them if the deer are fat.