442 



ANIMAL LIFE-HISTORIES 



what as in the form last described. Details are wanting, but the 

 young are said to hatch out as tadpoles. 



In some other cases there is a more or less well-developed 

 pouch for the reception of the eggs on the upper surface of the 

 mother's body. In a small Brazilian tree-frog (Hyla Goeldii], for 

 example, the skin grows out into a narrow fold surrounding an 

 oval area in which the eggs are placed, presenting an appearance 

 suggestive of a shallow dish full of pale-coloured oranges. There 

 is a large quantity of food-yolk, and the young have almost 



attained the form of 

 the adult at the time 

 they hatch out. In 

 the pouched tree - 

 frogs (Nototrema) of 

 tropical South Ame- 

 rica the female pos- 

 sesses a permanent 

 pouch on the upper 

 side of her body, 

 with an opening at 

 the back. The young 

 sometimes begin their 

 free existence as ad- 

 vanced tadpoles, but 



t - r , / ~ ei - ~f <-Vi^ cr^^i^c 



Fig. 966. Female of Surinam Toad (Pipa A mericana), carrying the 

 developing young on her back 



they have acquired 

 the adult form before they make their way out of the pouch. 



LIMBLESS AMPHIBIANS (GYMNOPHIONA ). The life -histories 

 of these curious burrowing snake-like creatures have not been 

 very exhaustively studied, but there are considerable differences 

 between those species which have so far been the subject of in- 

 vestigation. One of the Caecilians (Ichthyophis glutinosa, fig. 967) 

 native to South and South-east Asia is one of the least aberrant 

 species as regards development. The female excavates a hole in 

 damp earth close to a stream, and lays some two dozen large eggs, 

 round which she coils her body during their development. Shortly 

 before hatching, the tadpole stage within the egg possesses three 

 pair of long plume-like external gills of scarlet colour, and a pair 

 of gill-clefts. There is also a small tail-fin. The gills are lost 

 before the larva emerges, when it at once makes its way into the 



