TAKING THE EGGS. 1 03 



to give or receive impregnation is at an end. The 

 time for it has passed. No human power can after- 

 wards make milt or eggs anything but worthless. 



It has been estimated that the absorbing action of 

 the trout egg lasts thirty minutes in water. The period 

 of the activity of spermatozoa in water has been vari- 

 ously placed at thirty minutes, fifteen, ten, two, and 

 one and a half minutes;* the last two estimates being 

 nearest the truth. As will be seen by reference to M. 

 Vrasski's experiments, this period of activity is vastly 

 prolonged by not diluting the milt with water, f and the 

 chances of impregnating all the eggs are immensely 

 increased in consequence. For, according to the old 

 method of using water, either the spermatozoa died or 

 the eggs finished their absorbing process before there 

 was time for all the eggs to become impregnated ; 

 while by the new method of not using water the milt 

 has ample time to come in contact with all the eggs, 

 during the period of the activity of the one and the 



* The confusion on this point very probably arises from the 

 experiments being conducted in different temperatures of water, 

 the period of life of the zoosperms depending materially on the 

 temperature of the water. The zoosperms of trout milt do not 

 usually live over two minutes in water varying from 40 to 

 50 F. 



Quatrefages's experiments showed that the activity of the sper- 

 matozoa of different fish diluted with water lasted in the case of 

 the 



Brochet ... 8 minutes, 10 seconds. 



Mullet . . . 3 " 10 



Carp . . . 3 



Perch . . . . 2 " 40 " 



Barbel . . . 2 " 10 " 



t See p. 107. 



