PISCES. 



365 



termining the food value of a species. The improved devices 

 for capturing fish, the development of methods of preserving 

 them by drying and by canning, and the increased price of 

 other food substances for which fish may be substituted have 

 all conspired to increase the destruction of the more important 

 edible fish both in the fresh and salt waters. In recognition 

 of this, most nations have appointed commissions for the study 

 of problems connected with the fisheries and for the better 

 regulation of the same. The United States Fish Commission 



FIG. 181. 



FIG. 181. Brook Trout (Salvelimus fontinalis). From " Manual of Fish Culture," 



U. S. F. C. 



in conjunction with similar state boards, has done an im- 

 measurable amount of good especially in the following par- 

 ticulars : 



1. In taking the spawn of our most important food fishes 

 and caring for it artificially during the period of early develop- 

 ment when the young animals are in the greatest danger of 

 destruction. Such fish hatcheries are scattered all over the 

 Union and many of our fresh waters are being restocked with 

 species believed to be hardy and suitable for food. 



2. By determining the foods preferred by special fish and 

 artificially encouraging its abundance. 



