BULLETIN OF THE UNITED STATES FISH COMMISSION. 67 



Great Lakes. He would indeed be rash who would call upon the half- 

 developed science of fish culture under existing circumstances to mate- 

 rially increase the supply of food-fishes in the Great Lakes. Its mission 

 is rather to try and keep the supply up to three-fourths, two-thirds, or 

 even one-half of what these lakes formerly yielded. In 1871 there were 

 281 pound-nets being used in Lake Michigan, and 481 gill-nets. These 

 appliances were sufiicient to cause a continual decrease in the number 

 of fish contained in these enormous bodies of water, and, fish culture 

 aside, were sufficient to practically exterminate the fish in forty years. 

 But in 1879 the 281 pound-nets had been replaced by. 476 pound-nets 

 and the 450 gill-nets by 24,599 gill-nets. Steam- tugs devoted to fish- 

 ing, scarcely used in 1871, numbered 30 in that lake in 1879. Further- 

 more, the larger fish of the lake having been caught, it became neces- 

 sary to decrease the size of mesh of the nets, and to lengthen the nets. 

 So that, without doubt, there have been for several years nets enough in 

 use on Lake Michigan to reach entirely around the lake. Fish culture 

 aside, and without any additional efficiency in apparatus, it is only a 

 question of some ten years when the whitefish and trout fisheries will 

 be entirely exhausted. 



Fish culture is practically a science of the past fifteen years. It has 

 not yet reached a stage of efficiency which can cope with any such state 

 of affairs as present themselves on these great lakes. Even if $5,000,000 

 and fifty men are placed at the service of the State fish commissioners 

 in the interest of fish culture, what are these in the contest with 

 50,000,000 of people demanding food, and millions upon millions of capi- 

 tal naturally drawn upon to supply their need. The fruits of fish cult- 

 ure, like bread thrown upon the water, must return after many days. 

 It must wait the coming of the young fish to maturity before results are 

 apparent. The fishermen, however, reap the fruit of their labors on 

 the same day, if at all, and thus know the degree of success they are 

 attaining at any hour. With them it is largely a question of muscle ; 

 they put down their nets and haul up their fish. With fish culture it is 

 a serious question of scientific knowledge. It has not professed to yet 

 know many of the needed facts with reference to the embryonic life of 

 fishes, suitable temperatures of water, how to secure proper forms and 

 kinds of food, &c. These are questions which must be solved by care- 

 ful and continued study ; and, while the past ten years have been well 

 spent in this respect, there yet remains an enormous deal to be learned. 

 It is as if all agricultural implements, all knowledge in regard to seeds, 

 soils, climate, and treatment of vegetables were blotted out of existence, 

 and we had in ten or fifteen years to bring the science of agriculture 

 from nothingness up to where it could supply the wants of 50,000,000, 

 while but fifty or a hundred people were engaged in the effort, and aU 

 the remainder of the 50,000,000 were arranged practically in hostility 

 to their efforts. 



