IO 



this connection, as bearing upon the question of the 

 natural food for the young fish, immediately after 

 the absorption of the umbilical sac. I give the fol- 

 lowing minutes furnished me by Dr. P. N. Hagle, an 

 experienced microscopist associated with me in the 

 experiments. 



For five years I have directed my attention par- 

 ticularly toward the discovery of artificial food, or 

 otherwise, the natural aliment of the white fish dur- 

 ing its infantile stage, and my experiments and 

 observations have been attended with results exceed- 

 ingly satisfactory to myself, and as I feel, of the 

 greatest importance in their bearing upon the inter- 

 ests of successful pisciculture everywhere. I will 

 attempt to give you, briefly, a description of the 

 method I have pursued. 



About the middle ol November, 1873, I placed 

 some 1,800,000 of the ova of white fish in my hatch- 

 ing boxes, which received a constant supply of run 

 ning water at a temperature of 33 degrees. 



I also arranged in the same building, an additional 

 trough, through which flowed a stream of spring 

 water at an uniform temperature of 46 degrees. 



Knowing that the eggs would develop and hatch 

 in water of the latter temperature in sixty days, 

 while in that of the former it required one hundred 

 and thirty-five days, I was led to adopt such a mixing 

 of the two waters as should graduate the hatching 

 to such times as I desired. 



1 accordingly placed about 3,000 ova in the 

 spring water and hatched them about January 15th. 

 Of these I placed all except some 200 in a small 



