162 Amei'ican Fisheries Society 



These experiments show that unfertilized eggs live 

 longer than milt at the same temperature, and that the 

 sooner the milt is placed with the eggs the better. 



If the temperature is too low the trout spermatozoa 

 seem unable to enter the eggs for impregnation. If a 

 little warm water is used when the air is cold at spawn- 

 ing time the eggs are fertilized more successfully, and 

 this is especially true for the rainbow trout. The cross 

 between the rainbow and brook trouts cannot be made 

 successfully in cold water. 



Eggs were taken from a ripe brook after it had been 

 dead for an hour and a half, and fresh milt was added. 

 About 5 per cent, of the eggs were impregnated. 



A female and three male brook trout were taken in the 

 spawning season and put in a tank by themselves. On 

 November 2nd I took part of the eggs, again on the 5th 

 and the balance on the 9th, using the three males every 

 time. I could not see any difference in the impregnation 

 of these eggs. 



Some years ago, lake and brook trout were crossed by 

 Mr. Marks, of Michigan. These females produced eggs 

 and were again crossed with brook trout, making 

 hybrids three-fourths brook trout. 



Yearling brook trout, reared in a clay bottom pond 

 covered with shades, were transferred to another station 

 where they had sandy bottom and no shades. The bright 

 sun shining on the sand caused the death of nearly all of 

 them. The fish were curved up like a new moon or 

 quarter-round. Shades should be provided for ponds 

 with sandy bottom. I have known the sun to kill nearly 

 all the fry in a box tank, when the cover was lifted on 

 a bright day. 



