12 THE LIFE OF THE SALMON 



months' time. The adult fish are no doubt in great 

 numbers in those west coast American and British 

 Columbian rivers, yet the rivers themselves are of 

 vast size, and the amount of food for fry must be 

 practically unlimited. In any case we have no evi- 

 dence that smolts would starve in any of our rivers 

 if they did not descend when they do. No doubt 

 they get a greatly increased and varied amount of 

 food when they do go into the sea, but the time 

 when the migration takes place is the time when the 

 best feeding season is commencing, and it seems to 

 me necessary to take the natural instinct for a 

 temporary marine sojourn into account as well as 

 the need for increase of food. 



The time at which spawning takes place naturally 

 influences the condition of the fry, and possibly, 

 within limits, the time at which the smolt enters the 

 sea. We have in Scotland at the present time, when 

 account is taken of the Border rivers, considerable 

 variation in the limits of the spawning season. So 

 far as reports show respecting the times at which 

 fish are noticed spawning in the various Scottish 

 districts — which reports are published annually in 

 Part II. of the Fishery Board's Reports — there is a 

 difference between the earliest and the latest mean 

 periods of fully two months and a half If, however, 

 the Border rivers Tweed, Annan, and Nith are ex- 

 cluded — and they have been subject to special and 

 peculiar conditions — the difference in mean time 

 between Scottish districts is reduced to one month. 

 In other words, the height of the spawning season 

 in the earhest river, viz., November 7, is one month 



