142 ANIMAL BIOLOGY 



man of fishes as a source of food can scarcely be overesti- 

 mated. Unlike domestic animals, the fishes grow to maturity 

 without any care on the part of man. The fisherman has 

 only to provide the means to gather his harvest, while the 

 herdsman must care for his flocks and herds the year round. 

 Thus we see why fish are cheaper than other forms of flesh 

 food. 



While fish are most important to man as food, they have 

 other uses. Thus, for instance, the menhaden are caught 

 scarcely at all for food, but for the large quantities of oil 

 extracted from them. The remainder of their bodies is used 

 as fertilizer. It is estimated that about 3,000,000 gallons of 

 oil and 1,000,000 tons of scrap, with a total value of $2,500,000 

 is obtained annually by American fishermen from this kind 

 of fish. The oil extracted from the livers of cod forms a 

 valuable food preparation for invalids, since it is said to be 

 more easily absorbed and oxidized than any other known 

 fat. 



The great importance of fishes, however, is due to the fact 

 that they furnish a cheap and wholesome food. Nearly all 

 the parts of a fish are thus used. Not only is the flesh eaten, 

 but also the eggs (roe). The swim bladders, too, of many 

 fishes are made into isinglass which yields the highest grade 

 of gelatin. 1 Fish are eaten not only in a fresh condition, but 

 are also prepared in various ways. Among these methods 

 of preservation are drying, smoking, pickling, and canning. 

 Two of the more important fisheries are those of the salmon 

 and the cod. 



107. The salmon. The salmon (Fig. 107) is doubtless 

 the most important food fish of the world, and the Pacific 

 salmon completely outclasses all other forms. The Atlantic 



1 See article on isinglass in Cyclopedia. 



