56 HOW TROUT SPEND CHRISTMAS. 



pleting the great work of reproduction, seems to be as 

 follows : In all considerable rivers, where no insur- 

 mountable impediments exist, the trout, after completing 

 the spawning process in the shallow waters near their 

 source, take advantage of the ensuing autumnal floods 

 to return to the lower parts of the river, where they re- 

 main in the deep still pools, where the water near the 

 bottom will seldom or never be colder than 40 F., the 

 point at which it is the most dense and heavy. And 

 consequently, in a still pool of any considerable depth, 

 where there is no disturbing current, all the water of a 

 lower temperature than this, being of a less specific gravity, 

 will float on the surface until frozen into ice without the 

 temperature of the strata near the bottom being sensibly 

 diminished, as water is a very bad conductor of heat. 

 In those warm strata, the trout will be enabled to exist 

 in a comparatively mild temperature, even in the severest 

 season, no matter whether the surface is frozen or not ; 

 if so, so much the better, as the strata underneath will 

 be then effectually defended from the action of the cold 

 air above. It is my belief, at least, that all those fish 

 which have spawned sufficiently early in the autumn to 

 enable them to partially recover their strength and con- 

 dition before the severity of winter sets in, migrate back 

 again to the deeps in the lower parts of rivers, where 

 they continue to live and feed much in the same manner 

 as they do at other seasons, all the winter through ; and 

 where the enthusiastic votary of the rod may still pursue 

 his vocation with a limited amount of success, if he 

 chooses to follow them into their retreats with a well- 



