HALF HOURS WITH THE MAMMALS 



I. MAMMALS 



Some of the greatest artists have become famous by 

 painting scenes which typify the homes of farmers or 

 ranchers. In these the life of the husbandman is depicted 

 — beautiful fields with herds of cattle, flocks of sheep, or 

 droves of horses. They portray outdoor life so distinctly 

 that one can almost hear the lowing of the herds, and 

 catch the rich odor of new-mown hay and clover. 



Horses, cattle, sheep, and many others, composing the 

 highest forms of animal Hfe, are called mammals. They 

 differ from all the rest of the animals in their method of 

 caring for their progeny or young. These are nourished 

 upon milk, a fluid secreted in the so-called mammary glands. 

 Another peculiarity which separates the mammals from the 

 birds, reptiles, and fishes is that the body is more or less 

 covered with hair, instead of scales or feathers. 



The skeleton of a mammal (Fig. i) shows many differ- 

 ences from the lower forms. The bones, instead of being 

 hollow and light, as in the birds, are solid and ponderous, 

 the Hmb cavities being filled with marrow. The spinal 

 column, or vertebrae, is long and apparently divided into 

 several distinct regions, as the neck, the back, the loins, 

 and the tail. As a rule, there are seven bones in the neck 



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