MIGRATION OF SALMON. 215 



out in a smoother part of the pool towards its 

 middle, and many from a corner close by the left- 

 hand side cliflP, and these latter, the current not 

 being so rapid at that point, succeeded in making 

 good their ascent at fewer leaps than the others. 

 I am perfectly convinced from minute observation 

 that a grilse or salmon, having a sufficiency of 

 water to give the requisite impulsion to its salta- 

 tory powers can spring a distance of twelve feet, 

 and in some extraordinary instances a yard further 

 out of the water, in a direction slanting upwards, 

 nor is there any habit or practice on the part of 

 this interesting fish that excites my surprise more 

 acutely than its amazing locomotive capacity to 

 pass through, over and against the swiftest and 

 strongest rapids, whether deep or shallow. Salmon 

 ascend falls principally of mornings and after- 

 noons, and very few are seen making the attempt 

 between ten o'clock, a. m. and two o'clock, p. m. 



MiGPwATiON OF Salmon. — If all salmon de- 

 posited their ova at the same period of the year, 

 and if all ova were hatched in the same number 

 of days, which they would be if river water was 

 always of uniform temperature, then we should 

 have all salmon-fry of co-equal age, arriving at 

 the smolt state at the same time, and of course 

 migrating to the sea in vast shoals at one and the 



p 4 



