200 BACKBONED ANIMALS. 



the others being placed with equal care. Our common 

 triton lays its eggs singly on submerged plants ; others 

 are connected by a thread, whether on land or in the 

 water. 



Order IV. Blind Snakes (Gymnophiond] . The ani- 

 mals of this order are snake-like only in external appear- 

 ance and in name, having elongated cylindrical bodies 

 destitute of legs. The skin is smooth, containing imbed- 

 ded scales, and some species secrete in small pores a vis- 

 cous secretion similar to that of snails. The eyes are small 

 and beneath the skin. The Ccecilia of the tropics attains 

 a length of several feet, and lives underground like the 

 earth-worm, feeding upon insects. A Surinam species is 

 viviparous ; the young are born in the water and have 

 external, leaf-shaped gills, that are absorbed as they 

 leave it. 



Order V. Tailless Amphibians (Anura). We now 

 come to the frogs and toads, in which the body is short, 

 thick, and tailless in the adults, with four limbs, the hind- 

 er pair adapted for leaping. The skin covers the body 

 loosely, the muscles not adhering to it. The tongue is 

 fastened to the front of the jaw, the tip pointing down 

 the throat ; as a rule, the lower jaw is without teeth. 

 The eggs (Fig. 243, e) are deposited in jelly-like masses 

 in some pool ; in two weeks, more or less, the young ap- 

 pear, those of American toads being darker than those 

 of frogs. They now cling to the weed by little suckers 

 near the mouth parts, i ; branching tufts now appear on 

 each side of the head these are the gills, 2 ; the mouth 

 soon appears, the tufted gills are absorbed, and we have 

 the tadpole with six fish-like gill-slits. The legs are now 

 seen, 4, first appearing as little bumps under the skin, 

 and finally we have an animal resembling a lizard, with 

 four legs and a long tail, 5 ; the latter is gradually ab- 

 sorbed, 6 ; and the toad or frog crawls upon the shore in 

 perfect form, 7. 



