PROPAGATION OF FISH. 253 
equally well to tliem. 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. 
