PEOPAGATION OF FISH. 233 



same race, which has lately been found to exist in our 

 country, and which spawns in March, and the California 

 brook-trout which spawns in March and April. 



The salmon come in from the sea where they have passed 

 the cold weather, as soon as the ice breaks up, and keep 

 on all summer long running up into the fresh water ; which 

 alone is adapted to the fructification of their eggs. Trout, 

 in like manner, pass from the ponds and deep lakes into 

 the cooler streams, where a constant supply of fresh and 

 lively water can be obtained ; whitefish appear from the 

 depths of the great lakes and seeking the shallows along 

 shore, select gravelly and rocky reefs and springy spots to 

 lay their eggs. 



Salmon and trout make nests, the female digging out 

 the bottom and fanning away with her fins and tail the 

 mud and finer sand from the gravel which she afterward 

 uses to cover her eggs. When these operations are suf- 

 ficiently advanced, she is joined by the male and they 

 simultaneously, with one mutual impulse of amatory pas- 

 sion, deposit the eggs of the female and milt of the male. 

 Only a certain number of these are extruded at a single 

 impulse, and are then carefully covered over with gravel 

 by the female, while the male divides his time between 

 driving away intruders of his own sex, who would usurp 

 his prerogatives and devouring such stray eggs as may 

 have escaped the notice of his wife and been carried down 

 stream by the current. One noticeable peculiarity of the 

 spawn of this class of fish is, that the moment it falls 

 from the parent, it adheres to whatever it touches. This 

 is a provision of nature to enable the parent to cover it 

 over with gravel before it is washed away, which she 

 does with remarkable skill and care, moving the stones 



