144 



THE SEl-TROUT 



Fresh-water life ... ... ... 3 years "| 



Sea life without spawning ... 3 years li i years=2^ lb. 

 Sea life with spawning ... ... 5 years J 



It would naturally be of great interest if scales of old fish could 

 be found which would show a wide difference in the migratory habits of 

 fish of the same season's hatching, but one can easily understand that 

 the likelihood of securing such scales is not great because such fish 

 are relatively fewer in number; nor are the scales of old fish very 

 easy to read. There is no reason, however, it seems to me, why such 

 variation should not occur. From the set of scales upon which I have 

 so largely drawn for confirmation (so far as it goes) of my various views, 

 I have already cited (Fig. 48) one fish which apparently spent 3 years 

 in fresh water, thereafter 3 years in the sea without spawning, and 2 

 more years in each of which it spawned, the fish being caught in its 

 ninth year. As a contrast I cite later (Fig. 58) another fish which 

 apparently spent 2 years in fresh water, thereafter i year in the sea 

 without spawning and 5 more years in each of which it spawned, a total 

 of 8 years. 



It is unnecessary to follow any further in detail the individuals of 

 the shoal whose supposed movements we have been endeavouring to 

 trace. The same process of division and sub-division will I imagine 

 continue annually till few of those originally hatched together survive. 

 As the same process is moreover going on with respect to each year's 

 crop of smolts as these descend to the sea it is plain that the fish which 

 at any time are ascending will be of all sizes from the smallest to the 

 greatest. 



It would be interesting if one could discover the precise bearing 

 which the presence or absence of a loch, or a series of lochs, has upon 

 the migratory habits of the local sea-trout. I am inclined to think that 

 this matter may ultimately be found to be the key to many of the 

 problems that puzzle one in the life-history of the fish. It is at least 

 suggestive that enormous numbers of sea-trout are found in those 



