Generally, however, during the extreme drought, when unable to procure their ordinary food from the drying up of the watercourses, they bury themselves in the mud and remain in a state of torpor till released by the recurrence of rains.
Fig. 108.–Dorsal view of the skull of Crocodilus porosus. × about ⅙. Col, buttress connecting the postfrontal with the jugal and ectopterygoid; F, frontal; Jg, jugal; Mx, maxillary; Na, nasal; P, parietal; Pm, premaxilla; Pof, postfrontal; Pr.f, prefrontal; Q, quadrate; Qj, quadrato-jugal; R, the characteristic ridge on the prefrontal bone; Sq, squamosal; T, perforations in the premaxilla caused by a pair of lower incisor teeth.
C. porosus s. biporcatus.–The premaxillo-maxillary suture on the palate does not form a transverse line, but is W-shaped, and extends backwards as in the rest of the species of Crocodiles to be described. This Indian species is easily recognised by the prominent longitudinal ridge which extends in front of each eye, over the prefrontal bones, and by the absence of sub-occipital scutes. The nuchal scutes consist of four large ones, which form a square, and one or two smaller scutes on each side. The dorsal shield contains four to eight principal longitudinal rows. The digits, webs, and the serrated fringe of the legs are like those of C. palustris. The head and snout, however, are distinctly longer, and more slender in proportion, and the adult has only four teeth in each premaxilla. The general colour is dark olive-brown. Young specimens, as usual, are much paler and are spotted with black.
This species attains a much larger size than the Marsh Crocodile. Specimens of 15 to 20 feet in length are not uncommon, and there is a record of one monster of 33 feet. Consequently this is, both in bulk and length, undoubtedly the largest species of recent reptiles. It is essentially an inhabitant of tidal waters or estuaries, frequently entering salt water and going out to sea. Herewith corresponds its wide distribution, namely, the whole coast of the Gulf of Bengal, extending to Southern China, and across the Malay Archipelago to the northern coasts of Australia. Eastwards it ranges to the Solomon Islands and even to Fiji. Curiously enough, it does not seem to occur on the west coast of India.
According to Tennent it is ready to assail man when pressed by hunger, and the same authority mentions the following serio-comic incident. A man was fishing, seated on the branch of a tree overhanging the water, and to shelter himself from the drizzling rain he covered his head and shoulders with a bag folded into a shape common with the natives. While in this attitude, a leopard sprang upon him from the jungle, but missing its aim, seized the bag and not the man, and fell with it into the river. Here a crocodile, which had been eyeing the angler in despair, seized the leopard as it fell, and sank with it to the bottom.
I have had some personal experience in the bringing up of the young of this species. Two dozen of them had come from Ceylon when quite young, only one foot long. At first they were very shy, and huddled together in their tank, but they took food greedily–strips of fish and, later on, sheep's heart. When frightened they emitted peculiar, high-pitched, half-croaking sounds. Some of them snapped at the finger when touched; others were of a more gentle disposition; the shy ones were undoubtedly the most vicious. Within one year they grew to 18 or 20 inches, and added much to their bulk. Then they were transferred to a deeper and larger tank in a greenhouse, in which they could roam about at liberty. In the daytime they dozed on the margins of their pond, mostly in such a position that, at the slightest alarm, they could plunge back into the water. The strongest specimen left the tank entirely, and took up its favourite place for basking on the stump of a tree, to reach which it had to climb up a rough wall of stones. After three years, several had grown to the length of three and a half, and even four feet, and had by this time become formidable pets. Although handled frequently, they never became tame, the only change in their behaviour being that, instead of rushing off in a fright, and hiding for half an hour at the bottom of the tank, they became more vicious and confident, making for and snapping at the hand which fed them. The nights were spent regularly in the water, either floating with just the nostrils exposed, or in search of food, frogs being their favourite prey, while their main sustenance consisted of "lights," with an occasional mouse, or a piece of solid meat by way of an entrée. Small pieces were bolted. The tough "lights," namely lungs with the windpipe and blood-vessels, were causes of great quarrels. Two or three would get hold of a lump of this kind, tearing at it, and twisting and rolling over in opposite directions. The supply of warm water came through a stout pipe of red india-rubber, and this was an irresistible attraction to the crocodiles. On many a morning the tube was found twisted into a knot, one of the creatures having spent hours in chewing it and in trying to wrench it off. In order to aid digestion they swallowed pebbles. The most favourable temperature of the water was 85° F.; if below 75° F. they refused to eat, but a continued exposure to 60° F. did not hurt them. When the temperature rose above 95° F. they left the water, although means had to be taken to prevent them from lying on the hot-water pipes.
Fig. 109.–Dorsal view of the skull of a very old specimen of Crocodilus niloticus, in which most of the bony sutures are obliterated, × about ⅒.
C. niloticus s. vulgaris.–The premaxillo-maxillary suture on the palate is W-shaped. The nasal bones form only a small part of the posterior border of the nasal groove. There are eighteen or nineteen upper and fifteen lower teeth on each side. In old specimens some of the anterior mandibular teeth perforate the premaxillae, as indicated in Fig. 109, and they even pierce through the integument so as to be visible from above. The nuchals are composed of four large scutes, with a smaller one on each side and sometimes one behind, and there is a row of smaller pieces across the occiput. The dorsal shield contains six to eight principal longitudinal rows. The fingers are webbed at the base; the outer toes are very broadly webbed; and there is a serrated fringe on the outer side of the leg. The general colour of the adult is dark olive-brown; the young are paler, with black spots and vermiculations. The under parts are yellowish white.