Hans Friedrich Gadow

“ They spend most of their time in the water, but are also very fond of basking in the hot sun on the banks of rivers or in marshes, usually with the head turned towards the water, to which they take on the slightest alarm. ”

“ Specimens of more than 20 ft. in length are not uncommon, and a monster of 33 ft. is on record. It is essentially an inhabitant of tidal waters and estuaries, and often goes out to sea; hence its wide distribution, from the whole coast of Bengal to southern China, to the northern coasts of Australia and even to the Fiji islands. Australians are in the habit of calling their crocodiles alligators. C. cataphractus is the common crocodile of West Africa, easily recognised by the slender snout which resembles that of the gavial, but the mandibular symphysis does not reach beyond the eighth tooth. ”

“ Many a large mammal coming to drink at its accustomed place is dragged into the water by the lurking monster. Certainly there are occasional man-eaters amongst them, and in some countries they are much feared. ”

“ The vascular system has attained the highest state of development of all reptiles. The heart is practically quadrilocular, the right and left halves being completely partitioned, except for a small communication, the foramen Panizzae, between the right and left aortae where these cross each other on leaving their respective ventricles. The outer ear lies in a recess which can be closed tightly by a dorsal flap of skin. The power of hearing is acute, and so is the sight, the eyes being protected by upper and lower lids and by a nictitating membrane. ”

“ The skin of the whole body is scaly, with a hard, horny, waterproof covering of the epidermis, but between these mostly flat scales the skin is soft. The scutes or dermal portions of the scales are more or less ossified, especially on the back, and form the characteristic dermal armour. ”

“ They are often shed throughout life, the successors lying on the inner side, and with their caps partly fitting into the wide open roots of the older teeth. Especially in alligators the upper teeth overlap laterally those of the lower jaw, whilst in most crocodiles the overlapping is less marked and the teeth mostly interlock, a feature which increases with the slenderness of the snout. In old specimens some of the longer, lower teeth work their tips into deep pits, and ultimately even perforate the corresponding parts of the upper jaw. ”

“ As a rule, however, they are so wary and suspicious that they are very difficult to approach, and their haunts are so well stocked with fish and other game that they make off and hide rather than attack a man swimming in their waters. ”

“ They can walk perfectly well, and they do so deliberately with the whole body raised a little above the ground. When their pools dry up, or when in search of new hunting-grounds, they sometimes undertake long wanderings over land. ”

“ Other species, especially the alligators, make a very large nest of leaves, twigs and humus, scraping together a mound about a yard high and two or more yards in diameter. The eggs, in several layers, are laid near the top. The adults frequently dig long subterranean passages into the banks of streams, and, during dry seasons, they have been found deep in the hardened mud, whence they emerge with the beginning of the rains. ”

“ The Crocodilia form a separate order of reptiles with many peculiarities. The premaxillae are short and always enclose the nostrils. The posterior nares or choanae open far behind in the roof of the mouth, in recent forms within the pterygoids. The under jaws are hinged on to the quadrate bones, which extend obliquely backwards, and are immovably wedged in between the squamosal and the lateral occipital wings. The teeth form a complete series in the under jaw, and in the upper jaw on the premaxillary and maxillary bones. They are conical and deeply implanted in separate sockets. ”