582 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



and their larvse, water bugs and their larvae, salamanders, wagtails, &c, 

 so that by computation out of 1,000 eggs laid by the trout or salmon 

 under favorable circumstances, ouly oue young fish reaches the age of 

 one year. Nature scatters the seed with inexhaustible prodigality, but 

 seems to make the least use of it in the water. Besides this it must be 

 remembered that during the spawning season most fish come in large 

 schools to the surface and to shallow places, and are therefore more ex-- 

 posed to the persecutions of man in the spawning places than any- 

 where else. It is, therefore, all the more the duty of legislation to protect 

 these places in every possible way, and, wherever it can be done, to pre- 

 pare them in a suitable manner. 



As in artificial impregnation the roe and milt of the spawning fish are 

 pressed out by human hands, and brought into contact by stirring them 

 carefully in w 7 ater, the fertilization becomes more complete than in 

 nature ; by suitable breeding-apparatus the further development of the 

 eggs and the young fish are cared for. The better science succeeds in 

 finding out the conditions of life of the several species of fish, the nearer 

 nature can be imitated in this respect in the fish-breeding establishments, 

 the better one succeeds in removing all hurtful influences from the fish, 

 the richer will be the harvest, and the greater the economical usefulness 

 of such establishments. 



In selecting the species of fish, the quality of the water, as well as local 

 and commercial conditions, have to be taken into account. 



For artificial breeding, the finest and healthiest specimens of fish should 

 always be selected. Brook-trout, for instance, should weigh at least a 

 pound and be without a blemish. As with other useful animals, so espe- 

 cially with fish, the species selected is of the utmost importance for a favor- 

 able result of the trial, since it often requires long experience to find 

 out the proper places from which to get breeding fish. 



Streams or springs which have a considerable fall, fresh pure water, 

 and even temperature, are essential conditions to a favorable result of 

 artificial fish-breeding ; before entering the establishment, they should 

 have run for some time above «the ground, and received the oxygen, 

 which is necessary for the respiration of the fish ; they should likewise 

 be located near to good means of communication, especially railroads, so 

 that the impregnated eggs can be rapidly shipped to their destination ; 

 favorable places for catching small fish should be near; clearbrooks, which 

 are not so deep as to allow the entrance of large fish of prey, into 

 which the fish are to be transplanted from the hatching-houses, either 

 iu the immediate neighborhood or at least so located that they can 

 easily be reached ; finally, larger bodies of water, in which the fish- 

 ing-privileges are regulated in such a manner as to insure to the propri- 

 etors of the hatching-houses the full benefit of their efforts. The 

 chief and most essential point in artificial fish-breeding, however, is 

 in all cases to supply the growing fish with cheap and sufficient food. 

 The gain will be greatest iu those places where the food grows as it were 



