554 



AMPHIBIA. 



the help of phagocytes, some nourishment to other parts of 

 the body. The habit becomes less active, the structural 

 adaptations to the aquatic life disappear. " The homy jaws 

 are thrown off; the large frilled lips shrink up; the mouth 

 loses its rounded suctorial form and becomes much wider ; 

 the tongue, previously small, increases considerably in size ; 

 the eyes, which as yet have been beneath the skin, become 

 exposed ; the fore-limbs appear, the left one being pushed 

 through the spout-like opening of the branchial chamber, 

 and the right one forcing its way through the opercular fold, 

 in which it leaves a ragged hole '' (Marshall). 



While these changes are in progress, and as the supply of 

 food afforded by the tail begins to be exhausted, the tadpole 

 recovers its appetite, but is now exclusively carnivorous, 

 feeding on any available animal matter, or even on its 

 fellows. The change is not, however, so great as it seems, 

 for even at a very early stage animal food is eagerly 

 devoured. 



With the change of diet, the abdomen shrinks, stomach 

 and liver enlarge, the intestine becomes relatively narrower 

 and shorter. The tail shortens more and more, and as it 

 does so the disinclination for a purely aquatic life seems to 

 increase. Eventually it is completely absorbed, the hind- 

 limbs lengthen, and the conversion into a frog is completed. 



