TJie First Food of the Common White -Fish. 99 



their mouths; they did not die so suddenly. Jar No. 8 was sup- 

 plied witn sweet cream, but no evidence was afforded that the 

 occupants fed upon it. A quantity of rain-water was exposed to 

 the rays of the sun for tlie 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 tlie iish were seen to take into tlieir 

 mouths. Tliey 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 white-tish has been the 

 experience of the few fish-culturists who have hatched them." 



With the hope of ascertaining the natural food of tliese fishes, 

 a few specimens, representing young captured in the Detroit 

 River, and others from the hatchery, were submitted by Mr. Mil- 

 ner to Mr. S. A. Briggs, a microscopist, of Chicago. Four exam- 

 ples were examined by Mr. Briggs, two from each of the above 

 situations. Those from the hatchery contained nothing whatever, 

 while those from Detrttit River contained numerous specimens of 

 two species of Diatomace;e, viz., Frmiihirid capnr'uKt and StepJi- 

 anodiscus niagarce. The only fact at that time known would 

 consequently indicate that the earliest food of the species consisted 

 of Diatomacefe. 



The white-fisli, as is well known, lays its eggs in the open lake 

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

 spring. At this cold and stormy season in the exposed situations 

 where they are to be sought, it is practically impossible to find the 

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

 subject of unusual difficulty. There seemed, in fact, no practica- 

 ble way to reach satisfactory conclusions upon it except by exper- 

 iment upon individuals artificially hatched. 



In December, 1880, I made an arrangement, through the kind- 

 ness of Prof. Baird, of the Smithsonian Institution, witli Mr. F. 

 N. Clark, superintendent of the U. S. fish hatchery at Nortliville, 

 Mich., for a supply of young white-fish to be sent me at intervals 

 from the hatchery under his control. The specimens furnished 

 were taken from two lots. The fishes of one lot, hatched January 

 18, were kept in a tank in the hatchery, where they were supplied 



