Chapter III.

1. There is only one sense, that of touch, which is common to all animals; so that no exact name can be given to the part in which this sense resides, for in some animals it is the same, in others only analogous.

2. Every living creature is furnished with moisture, and must die, if deprived of this moisture either in the course of nature or by force. But in what part of the body this moisture resides is another question. In some animals it is found in the blood and veins, in others the situation is only analogous, but these are imperfect, as fibres and serum.[14] The sense of touch resides in the simple parts, as in the flesh and in similar places, and generally in those parts which contain blood, at least in those animals which have blood; in others it resides in the analogous parts, but in all animals in the simple parts.

3. The capacity of action resides in the compound parts, as the preparation of food in the mouth, and the power of locomotion in the feet or wings, or the analogous parts. Again, some animals are sanguineous, as man, the horse, and all perfect animals, whether apodous, bipeds, or quadrupeds; and some animals are without blood, as the bee and the wasp, and such marine animals as the sepia and the carabus,[15] and all animals with more than four legs.