482 BIOLOGY FOR BEGINNERS 



hawk, sharp-shinned hawk, great horned owl, and English spar- 

 row. 



3. Help preserve the forests and city trees for their nesting. 



4. Provide winter food for city birds. 



5. Provide nesting boxes for some city species. 



6. Try to inform others along these lines. 



Mammals. Food. This group includes the animals that we 

 usually think of as of the most importance to man. The ungu- 

 lates furnish his chief sources of animal food, since here belong 

 cattle, sheep, and pigs, and many others. Man uses as flesh food 

 practically all hoofed animals with four toes, and from cattle also 

 obtains, milk, butter, and cheese. Besides these, rabbits, squirrels, 

 bears, raccoons, opossums, seals, and even bats, monkeys, and 

 whales are important foods for man. In fact all mammals ex- 

 cept the cat and dog. families are used as food by some group of 

 people or other. 



Clothing. Next to their value as food, the mammal's chief 

 products are their body coverings, which man appropriates. 

 Sheep, goats, camels, and llama all produce valuable wools. 



The list of fur-bearing animals includes the otter, mink, ermine, 

 marten, and their relatives, together with foxes, wolves, bears, 

 tiger, leopard, and even the humble skunk, while the sea otter 

 and seal are much more valuable. The seal herd, belonging to 

 the United States is the most valuable Government possession in 

 the world. Leather is obtained from the hides of cattle, sheep, 

 horse, hog, goat, seal, walrus, buffalo, and many other mammals 

 and is absolutely indispensable because it has no satisfactory 

 artificial substitute. 



Various Products. The whale, largest of mammals, provides 

 several curious products; oil and a fine wax (spermaceti) are ob- 

 tained from some kinds. The oil whale also produces " whale 

 bone " which is made from a fibrous strainer device developed 

 from the roof of the mouth. Ambergris is an abnormal secretion 

 of the liver of sperm whales which is of enormous value as a 

 perfume. 



Horn and bone products of many mammals are used for making 



