THE MAMMALS 



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nipples to the mammary glands, but the ventral surface of the body is 

 covered by a broad milk field. When lunch time arrives the mother lies 

 on her back and the young crawl on her abdomen and lap up the milk 

 that flows out from the pores of the skin. 



Courtesy New York Zoological Society 



Fig. 28.2. The odd little duckbill of Australia seems to be made up of odd parts of 

 other animals. It is the most primitive mammal, laying eggs like birds. 



Photo by Winchester 



Fig. 28.3. A young opossum. 



