IMPORTANCE OF AMPHIBIA. 



127 



Like the Tailed Salamanders (Fig. 193), each common 

 Frog emerges from the egg in a larval form, totally different 

 from that of the full-grown Frog (Fig. 194). The short 



Fro. 193. Larva of Spotted Land-Newt (Salamandra maculata), from 

 the ventral side. In the centre a yelk-sac yet protrudes from the intestine. 

 The external gills are prettily branched and tree-like. The two pairs of 

 limbs are yet very small. 



FIG. 194. Larva of the Common Grass-Frog (Rana temporaries), a so- 

 called tadpole : m, mouth ; n, a pair of suction cups used in clinging to stones ; 

 d, skin-fold, which gives rise to the gill-roof ; behind are the gill-openings, 

 from which the gill branches protrude ; s, tail-muscles ; /, skin-fold of the 

 tail, forming a float. 



trunk is produced into a long tail, which in form and struc- 



42 



