300 



PROTECTION OF YOUNG 



N. Y. Zoological Soc. 



ment of cells considering the fact that 

 each animal originated as a single 

 fertilized cell. 



The kangaroo and the other mar- 

 supials, pouch animals, give birth to the young while these are 

 still poorly developed. The babies crawl into the pouch on the 

 mother's abdomen. The skin lining this pouch contains glands 

 that secrete a milky fluid by means of which the young kanga- 

 roos feed. All female mammals have well-developed milk glands 

 and normally suckle their young for a long or short period of time. 

 Some mammals are able to stand or walk immediately after 

 birth. This is true of the calf and of grazing animals generally. 

 Among other species, the new-born young is completely helpless. 

 The kitten does not open its eyes for several days. The human 



..-?>. -i 



N. Y. Zoological Soc. 



Care of young reaches its heights among the mammals. 



