128 Modern Fishculture in Fresh and Salt Water. 



hoochie river" (Jordan). But in the southern portion 

 of its habitat it is confiiied to streams in the Blue Ridge 

 and is not found in the warmer waters of the low lands 

 or near the coast. 



About 70° Fahr. = 17° R. or 22° Cent, is the limit 

 of heat that a brook trout will endure ; although if the 

 flow be very strong they may stand it for a little time, 

 but will suffer and die if the water does not cool soon. 

 On a cloudy, damp day a trout will live longer on land 

 than in water of 80° Fahr. 



Our lake trout cannot endure as warm water as the 

 brook trout can. It has its limit at about 65° Fahr. 

 For the rainbow and the brown trout it has been claimed 

 that they will endure water that is slightly warmer than 

 brook trout can stand, but I am not prepared to affirm 

 or deny the claim, never having submitted then to the 

 test. 



Ice on a trout pond will do no harm if the pond has a 

 circulation of water through it, but a shallow pond with 

 no flow that freezes entirely over, leaving no air holes, 

 is a deathtrap for fish of any kind. Such ponds are 

 common along the upper Mississippi, being merely holes 

 where the high water leaves many fish. I once chopped 

 through the ice on such a pond and there was a power- 

 ful odor of dead fish ; they had smothered. 



CHAPTER X. 



FOOD FOR ADULT TROUT MUSSELS. 



At Cold Spring Harbor, N. Y., I made trial of many 

 kinds of food for both adult trout and fry, in order not 



