METAMORPHOSIS OF A FROG 



i, tadpole just hatched; 2, 3, successively older tadpoles seen from one side; 4, a 

 slightly older tadpole seen from the dorsal side ; 5, a still older specimen from be- 

 low ; 6, tadpole with the gills covered, leaving only a small opening on the left side ; 

 7, indications of hind legs ; 8 and 10, successively older stages ; 9, specimen with the 

 ventral body wall removed, showing the coiled intestine and gills ; n, both pairs of 

 legs free; 12, 13, 14, successive stages in the resorption of the tail; 15, adult frog. 

 (After Leuckart and Nitsche.) (From " Synoptic Text Book of Zoology," by Weyss) 



102 



