THE SURINAM TOAD. 149 



at escape are foiled. Very little is known of the habits of this Snake, but it is thought 

 to burrow in loose ground. 



The color of the Atractaspis is blackish green above, shaded with orange-brown, and 

 orange-buff below. It is a small Serpent, rarely measuring more than two feet in length. 



THE BATRACHIANS are separated from the true reptiles on account of their peculiar 

 development, which gives them a strong likeness to the fishes, and affords a good ground 

 for considering these animals to form a distinct order. On their extrusion from the egg, 

 they bear no resemblance to their parents, but are in a kind of intermediate existence, 

 closely analogous to the caterpillar or larval state of insects, and Called by the same 

 name. Like the fish, they exist wholly in the water, and breathe through gills instead 

 of lungs, obtaining the needful oxygen from the water which washes the delicate gill- 

 membranes. At this early period they have no external limbs, moving by the rapid 

 vibration of the flat and fan-like tail with which they are supplied. While in this state 

 they are popularly called tadpoles, those of the frog sometimes bearing the provincial 

 name of pollywogs. The skin of the Batrachians is not scaly, and in most instances 

 is smooth and soft. Further peculiarities will be mentioned in connection with the 

 different species. 



These creatures fall naturally into two sub-orders, the leaping or tail-less Batrachians, 

 and the crawling Batrachians. The leaping Batrachians, comprising the frogs and toads, 

 are familiar in almost all lands, and in England are well known on account of their 

 British representatives. 



The tongue plays an important part in separating the frogs and toads into groups, 

 and in the first group the tongue is altogether absent, these creatures being in con- 

 sequence called Aglossa, or tongueless Batrachians. 



THE first of these creatures, the XENOPUS of Western and Southern Africa (Dactylethra 

 /cert's), is remarkable for possessing nails on its feet, the first three toes being tipped 

 with a sharply pointed claw or nail. The family is very small, comprising only one 

 genus, and, as far as is known, two species. The color of the Xenopus is ashy brown, 

 veined with blackish brown. It is rather a large species. 



THE celebrated SURINAM TOAD has long attracted attention, not for its beauty, as it 

 is one of the most unprepossessing of beings, but for the extraordinary way in which 

 the developement of the young is conducted. 



When the eggs are laid, the male takes them in his broad paws, and contrives to place 

 them on the back of his mate, where they adhere by means of a certain glutinous 

 secretion, and by degrees become embedded in a series of curious cells formed for them 

 in the skin. When the process is completed, the cells are closed by a kind of mem- 

 brane, and the back of the female Toad bears a strong resemblance to a piece of dark 

 honey-comb, when the cells are filled and closed. Here the eggs are hatched, and in 

 these strange receptacles the young pass through their first stages of life, not emerging 

 until they have attained their limbs, and can move about on the ground. 



The skin of this, as well as of other batrachians, is separated from the muscles of 

 the back, and allows room for the formation of the cells, being nearly half an inch 

 thick. The full-sized cells are much deeper than long, and each would about hold a 

 common horse-bean, thrust into it endways. The mouths of the cells assume an 

 irregularly hexagonal form, probably because their original shape would be cylindrical, 

 were they not squeezed against each other. 



When the young have attained their perfect state, they break their way through the 

 cover of the cells, and present a most singular aspect as they struggle from the skin, 

 their heads and paws projecting in all directions. In the museum of the College of 

 Surgeons may be seen some very good specimens of the Surinam Toad, some being entire, 



