TROUT PROPAGATION 



year, water that ranges from 62° to 70°, as this temper- 

 ature hatches the insect life, which constitutes a large 

 part of the food of trout. While food is all-important, 

 trout must have room also, in which to grow. It is 

 self-evident that if trout are planted in numbers to ex- 

 haust the food supply, they will not thrive ; but aside 

 from that trout must have space to be at their best, for 

 it has been demonstrated that a given number of trout 

 in a certain number of cubic feet of water will do bet- 

 ter than the same number of trout in half the quantity 

 of water, both lots of trout being fed the same amount 

 of food. 



How far trout may be acclimated to water of higher 

 temperature than that to which they are ordinarily ac- 

 customed has not yet been fully demonstrated. In 

 South Africa the brown trout has been hatched in 

 water as high as 79°, and in this country the rainbow 

 have been found to thrive in swift, well-aerated streams 

 that reach 85° F. The experiments of Dr. Davy 

 ("Physiological Researches") to determine the tem- 

 perature fatal to trout are of interest, and aside from 

 the question of temperature, as they show how trout 

 try to escape when the water becomes too warm. He 

 placed a common European trout (fario), or brown 

 trout of this State, of about a quarter of a pound 

 weight, into a good volume of water at 62°, which was 

 pretty rapidly raised to 75° by additions of warm water, 

 when it became very active and tried to leap out. In 

 an hour the water was increased to 80°, and after a few 



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