FItOGS AND THEIR RELATIVES 



115 



C, egg con- 



^, eggs before B, eggs after they taining young D, young tadpoles attaching 

 they are laid are laid tadpole themselves to a plant 



t 



E, young tadpole with ex- F, young tadpole with 



ternal gills internal gilla G, young tadpole with hind lega 



H, tadpole with webbed 

 feet 



/, tadpole with lega and arms 

 Fig. 84. — Life history of frog. 



J, young frog 



A, one-celled stage B, two-celled stage C, four-celled stage D, eight-celled stage 



B, aixteen-celled F, thirty-two G, sixty-four H, many-celled 



stage celled stage celled stage stage 



Fig. 85. — Cell division in a frog's egg. 



