PROPAGATION OF FISH. 253 



equally well to them. They remain in the fresh water 

 during the Winter, descend to the sea early in the Spring, 

 and return in June. They invariably return to the river 

 where they have bred, and in the course of their ascent 

 will overcome powerful rapids and considerable falls. 

 For a more full account of their habits, the reader is 

 referred to the appropriate title. 



