Considering its huge size and the character of its jaws and teeth as shown in [Figures 13 and 14], it is fortunate that it prefers fish to human flesh.
Anderson ([2]) describes the eggs and young of the Indian gavial. He found forty eggs in a nest of sand; they were in two layers, with a foot of sand between them. The young were 15.8 inches long at hatching. He says: “The young run with amazing rapidity the moment they are out of the shell.... Some of them actually bit my fingers before I had time to remove the shell from their bodies.” The following quotation from Oldenburg ([46]), for which I am indebted to Dr. Hussakof, is perhaps the earliest reference to the egg of the American alligator. It also mentions the habit that is practiced by some of the recent Crocodilia of swallowing stones to aid in digestion, as was apparently done by some of the large extinct reptiles.
“The eggs of Crocodiles and Alligators are little bigger than a Turkey’s. I thought to bring one to England, but it was lost. I never broke any to see the Yolk and White; but the Shell is as firme and like in shape to a Turkey’s, but not spotted. I inquired into the Stone in the Stomach of a Cayman or Crocodile, and I found by the inquiry of a very observing gentleman there, that they were nothing but several Stones, which that Creature swallows for digestion. He took out of one a piece of a Rock as big as his head: out of others he had taken sixteen or twenty lesser. None regards them much there, whatever Monardes relateth.”
CHAPTER II
THE SKELETON
A. The Exoskeleton
The exoskeleton is well developed in the Crocodilia, and forms a very considerable protection to its bearer. It is both dermal and epidermal in origin.
The epidermal skeleton of the alligator consists of oblong horny scales, arranged in transverse rows; the long axes of the scales are parallel to that of the body. On the tail, except along the mid-dorsal line, and on the ventral side of the trunk and head these scales are very regular in outline and arrangement; on the sides of the head and trunk and on the legs they are much smaller and less regularly arranged, while along the mid-dorsal line of the tail, especially in its posterior half, they are elevated into tall keels that give the tail a large surface for swimming. The first three digits of both manus and pes are armed with horny claws, which also belong to the epidermal part of the exoskeleton.
Fig. 15. Alligator Skins; Under-surface and Horn-back.
The dermal exoskeleton consists of bony scutes that underlie the epidermal scales of the dorsal surface of the trunk and anterior part of the tail. The overlying scales, except in very young animals, are always rubbed off, so that the bony scales are exposed. The ventral or inner surface of the scutes is flat, while the outer surface is strongly keeled and in old animals is often rough and pitted. The plates are nearly square in outline and are closely joined together in most places.