16 TO-AND-FRO MOVEMENTS OP SALMON 



and it is with considerable diffidence that I venture to 

 explain the impression I have received from the ascer- 

 tained facts. 



To begin with the salmon, even though it spends 

 the greater part of its life in the sea, and, after child- 

 hood, derives all its nutriment from marine creatures, 1 

 is a native of the river wherein it was hatched from 

 the egg and spent the first year, or two years, of its 

 existence. The river, therefore, must be pronounced 

 to be the home of the salmon. In its second or third 

 year it obeys the impulse which sends it to sea, where, 

 only, it can find enough food to satisfy the demands of 

 a constitution of extraordinary vigour. In the sea it 

 remains so long as those demands are clamant ; but 

 sooner or later the whole of that vigorous frame becomes 

 stuffed with nutriment, appetite fails, and the fish yields 

 to an impulse to return home and rest. Possibly that 

 impulse may be strengthened by a wish to escape from 

 seals, porpoises, and other predatory foes, and to get 

 rid of troublesome marine parasites. Anyhow, up come 

 the salmon to the scenes of their youth. Some, no 

 doubt, are acting under the nisus generativus ; their 

 ova and milt grow towards maturity, and in autumn 

 they go on the redds in the ordinary course. But 

 those fish whereof the ovaries remain undeveloped act 

 under no such stimulus. They simply want repose, 

 and, after lying in the river for some weeks or months, 



1 Be it far from me to renew in these pages the vexed controversy 

 as to whether salmon feed in fresh water after passing the sraolt 

 stage. I am merely stating the case as it appears to me, with all 

 respect due to those who hold other opinions. 



