The First Food of the Common White-Fish. 
99 
their mouths; they did not die so suddenly. Jar No. 3 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 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 white-fish 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. 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 Detroit River contained numerous specimens of 
two species of Diatomaceae, viz., Fragilaria capucina and Steph- 
anodiscus niagarce. The only fact at that time known would 
consequently indicate that the earliest food of the species consisted 
of Diatomaceas. 
The white-fish, 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, with Mr. F. 
N. Clark, superintendent of the U. S. fish hatchery at Northville, 
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 
