In temperate climates serpents as a rule are less fierce than in the tropics. In North America the Crotalida comprise twelve species with rattles, and three species in which rattles are absent. Of the last named, the copperhead and moccasin snakes are well known. Of the first, the northern rattlesnake (Fig. 7) is familiar, and unpleasantly abundant in many parts of the country, but is nowhere fierce or inclined to attack. Fig. 8 is of the common viper, or adder of England and the Continent.

All the gigantic crushing species are found in regions of torrid temperature. Of these, the Guinea rock or fetich snake (Fig. 10) is allied to the family of pythons already noticed.

There too are the most terribly fierce of the venomous species, as the fer de lance (Fig. 11); the cobra (Fig. 12), sacred in India, the killing of which with some tribes is considered sacrilege; the haje or spitting-snake of Africa, a hooded species, and allied to the cobra, and the horned puff-adder (Fig. 13), whose poison is used to tip arrows by the South-African Bushmen.

The mere recital of their names excites in one unpleasant sensations. Deaths from the bite of serpents in temperate regions which they infest are surprisingly rare. It is otherwise, however, in the tropics, and perhaps no country has so fearful a mortality from the bites of venomous snakes as India. In six provinces, which include Assam and Orissa, with a population of about 121,000,000, 11,416 deaths were reported in a single year. This is about one in every 10,000 of population, and this is only an approximation to the actual mortality, for many districts sent no returns. A majority of all the deaths from this cause was from cobras; yet this serpent, as ob

served, is an object of veneration, and is regarded with peculiar deference. If found in their houses, as it frequently is, it must be petted, cared for, tenderly fed, and propitiated, for it is an object of worship, and occupies a high place in the mythology of the Hindoos. Indeed, the worship of serpents seems to have been widely adopted, and figures more or less in a vast number of the religions of the world. It is often referred to in the Scriptures, and is a subject of elaborate discussion in the profoundly learned and interesting volume of Ferguson, on "Tree and Serpent Worship."

We mentioned the fact that in most species serpents have but one fully-developed lung. Into the cavity of this the trachea or windpipe terminates, and it has been stated that they "in a manner swallow air." What takes place in the process of breathing appears to be this. Unlike mammals, serpents have no diaphragm, but by a movement of the ribs the cavity of the body is enlarged, and, a pressure being thus removed, the lung inflates and expands by the air passing into it. Another and opposite movement of the ribs expels the air, whence it appears that their process of breathing is essentially the same as in mammals. Nor are their lungs in structure essentially different. The air sacs or cells communicate with the principal pulmonary tube, but a vastly smaller surface is exposed to the inhaled air, and aëration of the blood is consequently extremely imperfect and incomplete.

Serpents are without proper organs of voice, the vibrating membranes being absent. The passage of air into and out of the lungs, if hurried and rapid, produces a hissing noise, the only voice possible to them, but which we fear makes less interesting their somewhat unprepossessing features.

A scale-like covering, which is fixed and immovable, covers the eye of the serpent, as shown in Fig. 4, and gives to it, as Prof. Nicholson vividly expresses it, the "peculiar, stony, unwinking stare" for which they are remarkable, and which, when they are enraged, becomes intensely fierce.

This covering is evidently transparent, as the animal distinguishes forms, but in the cast-off skin it is translucent only. Behind the eyeball is a lachrymal gland, with a duct which conveys tears to the membranes of the eye. By this means they are kept moist. A conduit connects the eye-cavity with the olfactory opening, and, should the creature shed tears, it would be through that opening, not directly from its eyes.

In common with other animals, serpents have some habits and

instincts peculiar to themselves, which are directly related to the necessities of their being; but we are not aware that they display great sagacity, cunning, or wisdom. They are not fertile in devices, not especially artful, and the extreme simplicity and smallness of their brain indicate their low mental powers.

The entire tribe of serpents for the purposes of this paper may be divided into the venomous and non-venomous species. Of the nonvenomous, we will pass, with one or two remarks, the interesting families of double walkers, and slow or blind worms (Fig. 14), types which are structurally intermediate between true serpents and lizards. The first of these derives its name from the fact that it can progress

with facility forward or backward; the second from the erroneous notion that it has no eyes. To this class belong the curious glasssnakes, so named from their fragility. Other non-venomous serpents comprise the inoffensive and harmless, and some of the most terrible species. Of these we have noticed the gigantic rock-snake or python of India, which attains a length of 30 feet. The Natal rock-snake is found 25 feet long. Of equal size is the boa-constrictor of tropical America, formerly an object of worship. The anaconda, or waterserpent, which frequents the rivers of Brazil, and watches for its prey along their banks, is sometimes more than 25 feet long. These are

among the most powerful of their kind, in whose folds man is helpless, and bones of goats and cattle are broken with a crash which, it is said, may be heard many rods. We turn from these, whose fearful presence we associate with the splendors of tropical forests, to species harmless and often serviceable to man, yet everywhere persecuted by him. Among these we find the beautiful ring and grass snakes of our gardens; the milk and striped or garter snake; the common adder (so called), but entirely harmless; the active black snake or racer, found nearly everywhere in the United States. More dreaded because more dangerous than the gigantic species mentioned, are the venom

ous serpents, not powerful in strength or immense in size, but fierce in some cases, and in their attack deadly. The largest of these is said to be the bush-master, found in British Guiana, which, on the authority of Waterton, attains a length of fourteen feet. But the belted hamadryad of Burmah is often seen twelve to fourteen feet in length, and is a foot in circumference; and it is stated that specimens have been seen. three fathoms (eighteen feet) long. If so, it is probably the largest known venomous serpent. This terrible creature feeds on other snakes, hence its scientific name, Ophiophagus elaps. Others, as the cobra and the rattlesnake, are relatively small, rarely attaining a length greater than six feet, usually not more than four feet.