ADAPTATIONS 



339 



with almost all mammals the o<rg is very small and without 

 much food yolk. The egg begins its development within tiic 



r~ 



>v/' 



1 





in.. I'J'J. — Jvai.^;. .;.',,, Macropus rufus, with young in pouch. 



body. It is nourished by the blood of the mother, and after 

 birth the voims; is cherished bv her. and fed bv milk secreted 

 by speciaUzed glands of the skin. All these features are 



