24 INTRODUCTION TO THE EMBRYOLOGY OF THE LEOPARD FROG 



mum point of 96 per cent water (Davenport, 1899, Proc. Bost. Soc. 

 Nat. Hist.) This imbibition accounts for the apparent acceleration of 

 growth of the newly hatched tadpole, but it is not related to an in- 

 crease in total mass since there is no immediate intake of food. The 

 growth rate is affected by various environmental factors such as space, 



Metamorphosis of the frog, Rana catesbiana. {Reading from left to right, top 

 and bottom) : Tadpole; tadpole with hind legs only; tadpole with two pairs of 

 legs; tadpole with disappearing tail, ready to emerge from water to land; im- 

 mature terrestrial frog; mature frog. 



