44 THE SALMON. 



migrated in its first year; but that is now quite exploded. 

 Almost all the writers against Mr. Shaw maintain that 

 the migration takes place at the commencement of the 

 second year; that is, that being hatched in March or 

 April, the parr descends to the sea in May twelvemonth. 

 It is thus admitted that it does not avail itself of the 

 first season of migration occurring after it has been left 

 to its own resources and instincts. Now, is not this as 

 much of what we, in our ignorance of the natural history 

 of fish, regard as an anomaly, as is the staying over a 

 second season of migration ? The question, then, must 

 be considered without any regard to apparent anomalies, 

 and decided only on the evidence of experiment and 

 observation. 



Apart from the experiments that have been made 

 under circumstances permitting the closest observation, 

 there is a fact observable in all salmon rivers, which, if 

 it does not fully establish, remarkably coincides with the 

 two years' theory. In the months of May, June, and 

 July, full-sized parrs are to be got in the rivers, but in 

 numbers much smaller than in either the preceding or 

 the following months of the year. This, it will be seen, 

 fits in exactly to the two years' hypothesis, which says 

 that multitudes of the fish hatched two years before, and 

 which were parrs in March and April, descend in May as 

 smolts, and that the fish which were hatched that same 

 year remain till autumn of diminutive size and retiring 

 habits, so that the parrs seen in the rivers in the months 

 of May, June, and July, are mainly those only of the 

 previous year's hatching, i.e., of from thirteen to sixteen 

 months of age those of a year older than that having 



