MIGRATION. 167 



sea, and enter the estuary of their chosen river; 

 here they lie, advancing with the flood tide, 

 and retiring with the ebb. As the season pro- 

 gresses, they ascend higher up the river, so as 

 to escape the influence of the tide, and are now 

 getting into full roe. " Their progress for- 

 wards is not easily stopped ; they shoot up 

 rapids with the velocity of arrows, and make 

 Avonderful efforts to surmount cascades and 

 other impediments by leaping, frequently clear- 

 ing an elevation of eight or ten feet, and gain- 

 ing the water above pursue their course. If 

 they fail in their attempt, and fall back into 

 the stream, it is only to remain a short time 

 quiescent, and thus recruit their strength to 

 enable them to make new efforts." The salmon 

 deposits its spawn in September, October, and 

 November, and returns to the sea. u With the 

 floods of the end of winter or commencement of 

 spring, the salmon, male; and female, descend 

 the river from pool to pool, and ultimately gain 

 the sea, where they quickly recover their con- 

 dition, to ascend in autumn for the same pur- 

 pose as before." The descent of the. young fry 

 to the sea begins in March, and continues 

 through April and May. Here, then, we have 

 an example of periodical migration, but on a 

 limited scale ; nevertheless, we cannot deny 

 that it is true migration — a migration from the 

 deep sea to the highly aerated water of the 

 pure river. 



As we are now attending to the migration of 

 fishes, which, we contend, is very partial, even 



