The cobra belongs in the group called the colubrine snakes, a family which comprises both harmless and noxious types of snakes. The cobra is a member of the latter, having fangs and one to three solid teeth behind them. The body is cylindrical, with the smooth scales disposed in fifteen or more oblique rows; while the tail is of moderate length, with its inferior shields in either a single or double series. The dilatation of the neck, which always takes place when they are excited and about to strike, at once serves to distinguish cobras from other snakes.
Cobras are confined to Africa and Southern Asia, and are represented by six or seven species, two of which are found in India. Of the Indian forms, by far the most abundant is the common or true cobra. Distinguished by having no large shields on the head behind the parietals, and by the whole of the shields on the under surface of the tail being arranged in a double series, this snake is a very variable species as regards coloration, some examples having a dark spectacle-like mark on the back of the hood, while others have onlya single eye-like spot, and others, again, have no mark at all in this region. In regard to coloration, the hue of the upper-parts may be greyish brown or black, with or without a spectacle- or loop-shaped black light-edged marking on the neck- or with light spots or crossbands on the body; while beneath it varies from whitish, though brownish, to blackish, sometimes with black crossbars on the fore-part of the body. Occasionally attaining a length of a few inches over 6 feet, while an instance is on recorded where a specimen measured upwards of 7 feet 3 inches, this cobra is distributed over the whole of India and Ceylon, ranging westwards through Afghanistan to the Caspian, and to the east of the Malayan region, and the south of China. The other Indian species, or giant cobra is a larger snake, distinguished by the presence of a pair of large shields on the head behind the parietals, while the shields beneath the tail usually form only a single series. When adult, its color is yellowish or brown, with more or less distinctly marked dark crossbands; but young specimens are usually black, with yellow rings on the body and bars on the head, and in some instances there are light spots on the upper surface, and the inferior shields are whitish with black margins. In size, the giant cobra is known to measure as much as 13 feet, and probably grows larger. Fiercer than the common species, this cobra is fortunately far less abundant; its range extending from India through Burma and Siam to the Malayan region and the Philippines. Another species is the asp or Egyptian cobra, which is widely spread over Africa, and presents great variations in color. Somewhat exceeding in size the true cobra, the asp is distinguished by the sixth upper labial shield of the head much exceeding the others in length, and uniting with the temporal, so as to form a large plate, which anteriorly comes in contact with the postocular shield. In most Egyptian examples the color of the upper parts is uniformly straw-yellow, while the under-parts are light yellow; but there may be dark crossbands on the under surface of the region of the neck, which sometimes unite into a patch. The straw-color may, however, shade into blackish brown and occasionally the hues may be brighter.
The account of the habits of these snakes will be mainly confined to the common Indian species. Although frequently seen in motion during the day, cobras are most active during the night; and they feed chiefly on small mammals, birds' eggs, frogs, fish, and even insects. The giant cobra subsists, however, almost entirely on other snakes; and the other species will occasionally rob hens' nests, swallowing the eggs whole. In captivity, cobras will live weeks and even months without tasting food of any kind or touching water. Although essentially terrestrial, they will readily enter water, in which they swim well; while they occasionally climb trees in search of food, and are often found, more especially during the rainy season, in old buildings and walls, or in wood stakes and heaps of rubbish. It is when collected in such situations that they are most commonly trodden upon by the local peoples- and more frequently at night than at other times- with the well-known fatal results.
These snakes lay from eighteen to twenty-five oval eggs about the size of those of a pigeon. Ascending to a height of some eight thousand feet in the Himalaya, the common cobra is dreaded and fatal when met; fortunately it is not naturally aggressive, unless provoked, at which times its aspect is most alarming. Raising the anterior third or more of its body, and expanding its hood, with a loud hissing, it draws back its head prepared to strike, and, when it does so, darts its head forwards, and either scratches, or seizes and imbeds its fangs in the object of attack. If the grasp be complete and the fangs imbedded in the flesh, dangerous and often fatal effects result; but if the fangs only inflict a scratch, or if the snake be weak or exhausted, the same great danger is not incurred. If the poison enters large vein and be quickly carried into the circulation, death is very rapid; men have been known to perish from cobra-bite within half and hour. The largest and strongest as well as the smallest and weakest creatures succumb; but fortunately, all who are bitten do not die. In the first place, some human beings, as well as lower animals, have greater tolerance than others of this or other poisons- a result, doubtless, of idiosyncrasy or varying degrees of nervous energy which enables one to resists that to which another would yield; or a wound may have been inflicted and yet but little of the poison inoculated; or, in the third place, the snake may be weak or sickly, or it may have been exhausted by recent biting, and thus have become temporarily deprived of the power of inflicting a deadly wound. But when a cobra in the full possession of its powers bites, and injects the poison into man or beast, it is almost surely fatal, and all the remedies vaunted as infallible antidotes are futile.
