2380. The shoulder appears to consist of five ribs, but this does not as yet admit of being clearly pointed out. Meanwhile, it is certain that the scapula, acromion, and coracoid are particular bones, to which may be added the clavicle.
2381. The middle finger is the elongated radius, and is therefore the longest or radial digit. It is that which is persistent, if only one finger has been left, as in the horse. The ring-finger is the ulnar finger. It is that which, along with the former, appears in the bi-ungulate animals; the spurious or dew-claws are the auricular and index-finger; the thumb is the last ramification, is therefore always arrested, and frequently present only as a wart-like excrescence or papilla.
2382. All animals, which have true digits, are furnished with five of them, more or less completely developed. If what has been called the metacarpal bone of the thumb be numbered, which it must, as a digital articulation or phalanx, every finger has thus one carpal bone, and each bone of the fore arm also one.
2383. The sexual members or feet correspond in all their pieces to the arms: the pelvis is the shoulder repeated; and certainly, the iliac bone is equivalent to the scapula, the ischium to the coracoid process, the os pubis to the acromion, the marsupial bone to the clavicle.
Cephalic Members.
2384. Both pairs of limbs are repeated in the head, because in it the whole trunk is repeated; the upper jaw corresponds to the arms, the lower jaw to the feet. Each jaw consists of two members, which are ankylosed in the higher animals at their point of meeting or in front, but in Fishes are partly, and in Insects completely, separated.
2385. Each jaw consists of the same bony divisions as the limbs of the trunk, of scapula, humerus, and fore-arm; or of pelvis, femur, and tibia. This is easily to be demonstrated in Birds, Reptiles, and Fishes.
2386. The digits are repeated in the teeth. The teeth are claws.
2387. There are therefore five kinds of teeth, which correspond to the five digits. The thumb becomes the canine tooth; the index-finger the false molars; the middle finger the laniary molar, the ring-finger the second, and the little finger the third true molar tooth.
2388. The intermaxillary with its incisor teeth belongs, as well as the palatal bones, to the pharynx; and is a visceral or intestinal maxilla.