774 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [4] 



l^lyiug them with d number of articles of food, iu the hope of lindingr 

 something suitable for their nourishment. 



"A few crawfish," he says, "were procured and pounded to a paste, 

 and small portions put into jar No. 1 ; the young fish ate it readily. 

 They were fed at night, and the next morning every one of them was 

 found to be dead. Jar No. 2 was supplied with bread crumbs, and the 

 fish were seen to take small particles in their mouths ; they did not die 

 so suddenly. Jar No. 3 was supplied with sweet cream, but no evi- 

 dence was afforded that the occupants fed upon it. A quantity of rain- 

 water was exposed to the rays of the sun for the purpose of generating 

 minute forms of life, and a teaspoonful was poured into jar No. 4, 

 morning and evening, in the hopes that their proper food was of this 

 character. In jar No. 5 a variety of food was provided — dry, fresh beef, 

 milk, boiled potato, and bread. The crumbs of bread and the scrapings 

 from the beef were all that the fish were seen to take into their mouths. 

 They died, one after another, very rapidly, and in a few days all were 

 dead." He further remarks: "This difficulty of procuring a suitable 

 food for the young whitefish has been the experience of the few fish- 

 culturists who have hatched them." 



With the hope of ascertaining the natural food of these fishes, a few 

 specimens, representing young captured in the Detroit River, and others 

 from the hatchery, were submitted by Mr. Milner to Mr. S. A. Briggs, 

 a microscopist, of Chicago. Four examples were examined by Mr. 

 Briggs, two from each of the above situations. Those from the hatchery 

 contained nothing whatever, while those from Detroit Eiver contained 

 numerous specimens of two species of Diatomacese, viz, Fragilaria ca- 

 pucina and Stephanodiscus niagarce. The only fact at that time known 

 would consequently indicate that the earliest food of the species con- 

 sisted of Diatomacete. 



The whitefish, as is well-known, lays its eggs in the open lake iu 

 autumn, the young not appearing until early in the following spring. 

 At this cold and stormy season, in the exposed situations where 

 tliey are to be sought it is practically impossible to find the young 

 fish; a fact which rendered the study of their earliest food a sub- 

 ject of unusual difficulty. There seemed, in fact, no x)racticable way to 

 reach satisfactory conclusions upon it except by experiment upon indi- 

 viduals artificially hatched. 



In December, 1880, I made an arrangement, through the kindness of 

 Professor Baird, of the Smithsonian Institution, with Mr. F. N. Clark, 

 superintendent of the United States fish hatchery at Northville, Mich., 

 for a sujjply of young whitefish to be sent me at intervals from the 

 liatchery under his control. The specimens furnished were taken from 

 two lots. The fishes of one lot, hatched January 18, were kept iu a 

 tank iu the hatchery, where they were supplied with water from a 

 spring, which had been cooled by exposure to the air in artificial ponds 

 before entering the hatchery, in order to retard the development of the 



