68 THE MICHIGAN ACADEMY OF SCIENCE. 



fore, it would seem reasonable to attribute most of the increase to 

 protected propagation. (Remarks.) 



Since 1898 the work of hatching and planting the commercial fishes 

 in the Michigan waters of the Great Lakes has been wholly confined to 

 work of the United States Fish Commission, now known as the Bureau 

 of Fisheries, Department of Commerce and Labor. (Remarks.) 



It has been the aim of the bureau to extend this work so far as the 

 limited appropriations will permit. At present the government main- 

 tains two regular stations or hatcheries and three auxilliaries in 

 Michigan. 



The method used in the collection of whitefish eggs is to seine as many 

 parent fish as possible from the spawning grounds of the Detroit river 

 at the approach of the spawning season and hold them in crates (re- 

 marks) until ripe, when they are stripped and the eggs transferred to 

 the Detroit hatchery, and developed to the eyed stage; a portion of them 

 are then distributed to the auxiliary stations for hatching and planting. 

 The remainder are hatched and planted in the Detroit river. 



Since the inception of the work our vearly collection of whitefish eggs 

 has been from 200,000,000 to 350,000.000, which were nearly all hatched 

 and planted in Michigan waters. 



Operations for the collection of lake trout eggs have been conducted 

 principally at Beaver Islands and Manistiipie in upper Lake Michigan. 



Fishing for lake trout is done with tugs and gill nets. The eggs being 

 stripped from the ripe fish as soon as taken from the nets and transferred 

 to the Northville station; developed to the eyed stage, then all dis- 

 tributed to the auxilliary hatcheries for hatching and planting. Our 

 annual collection of lake 'trout eggs is from 10,000,000 to 30,000.000. 



The auxilliary stations are located in close proximity to the best plant- 

 ing grounds, and the object is to obviate the transfer of large quantities 

 of small fry for long distances and take the risk of loss. They are much 

 more easily transferred as eggs, and the fry are planted in much better 

 condition. (Remarks.) 



To extend this work should be the aim of the national government. 

 And to abolish some of the present useless laws, and a rigid enforce- 

 ment of the remainder, should be the duty of the State, and an exhaustive 

 research for some system of disposing of sewage without polluting the 

 waters, should be commenced. 



The amount of living fish germs that may be brought to life and 

 planted in waters, is no harder problem to solve than to develop a given 

 quantity of electric power, ])rovided the parent of these germs is taken 

 at or near the harvesting time. We can as well turn out billions of 

 young fry as millions, if means are forthcoming for the Avork. 

 Frank N. Clark, Su])!. of V. S. Hatcherv, 

 North vi lie, Mich. 



