184 Modern Pishculture in Presh and Salt Water. 



method stated later on. If it is possible to take large 

 numbers of parent fish at the precise time when the eggs 

 are fully matured and ready to be cast, with an adequate 

 force of strippers, a good percentage of impregnation 

 may be secured. The season when this fully ripened 

 -condition is reached is comparatively short, and the un- 

 certainties surrounding the work are so many that re- 

 sults are always problematical. The fish linger about 

 the spawning grounds for some time, but the period 

 covered by the actual act of spawning is brief. To se- 

 cure the highest percentage of fertilization the eggs 

 must be thoroughly ripened and the impregnation must 

 take place under the most favorable conditions. Those 

 taken before this ripened time arrives give poor results 

 and a low percentage of impregnation, the percentage 

 depending upon the closeness to the condition above 

 mentioned. 



In making this method of collection a crew of strip- 

 pers and helpers sufficiently large to handle the greatest 

 number of fish in the shortest possible time is put on the 

 fi.shing tugs or boats, equipped with all the necessary ap- 

 pliances for the work, The boats go out to the fishing 

 grounds and begin lifting the nets. While they are 

 being taken in the gravid females are relieved of their 

 eggs and they are artificially fertilized. The same 

 method is followed in the impregnation of the eggs of 

 the whitefish as in the fertilization of trout eggs. These 

 operations are usually conducted under many difficul- 

 ties. The locality is the open lake with the rough seas, 

 which are common in the autumn ; the temperature is 

 usually about the freezing point. The decks of the 

 boat, more or less covered with ice, are crowded with 

 the fishing crew and the strippers and encumbered with 

 the usual paraphernalia of the boat and the utensils of 



