MAN'S CONQUEST OF NATURE 575 



(Hevea hrasiliensis) and other rubber-producing plants, various resins 

 and gums, tannin, and cork are all important forest products. 



Uses of Animals 



It would seem unnecessary to list all of the animal series that man 

 uses as food, but we cannot look at the census statistics without seeing 

 the direct value in dollars and cents of our meat-producing mammals. 

 Three bilhon dollars' worth of such animals is a pretty large investment, 

 even in so rich a country as the United States. In addition, there are 

 the various products which come from cattle, namely, milk, butter, 

 cheese, and leather. A few wild mammals such as deer, bears, and, in 

 the arctic regions, seals and walruses are also used for food. Birds 

 both wild and domesticated, and their eggs, form part of our food 

 supply, although wild game birds are disappearing so rapidly that we 

 cannot consider them as a source of food except among the Eskimos 

 of the arctic region. Amphibians, for example the large bullfrogs, fur- 

 nish food for epicures, while some reptiles, such as the iguana and 

 even snakes, are eaten in some parts of the world. There are edible 

 salt-water turtles, too, many of large size, the leatherback and the 

 green turtle often weighing six to seven hundred pounds each. The 

 flesh of the diamond-back terrapin, an animal found in the salt marshes 

 along our southeastern coast, is highly esteemed as food. 



Fish is a food the world over. Among fresh-water species, white- 

 fish, pike, and the various members of the trout family are valued 

 food and, especially in the Great Lakes region, are so abundant 

 as to warrant the establishment of important fisheries. By far the 

 most important food fishes, however, are those which are taken in 

 salt water. 



Among invertebrates used for food the much desired lobster should 

 not be omitted. Because of the esteem in which it is held, it has been 

 almost exterminated in many localities. The canning of lobsters, 

 crabs, and shrimp ranks as an important industry in many parts of 

 the world. Molluscs, especially oysters, clams, and scallops, are 

 much sought as delicacies, and form the basis for important industries, 

 particularly along our eastern coast. Lower forms are little used as 

 food although the Chinese are very fond of holothurians, which are 

 preserved by drying and are called "trepang." In the West Indies 

 the soft parts of sea-urchins are considered a delicacy. Finally, the 

 honey-bee furnishes us with honey, of which over 60,000,000 pounds 

 are used every year in this country. 



