NATURAL HISTORY OF THE SALMON. 79 



What we say is, that the wide range of size and weight 

 in the case of sahnon shows a wide range of ages and 

 circumstances, and that the comparatively small range 

 of size and weight in the grilse, we shall not say proves, 

 but indicates, a very much narrower range of ages and 

 circumstances. 



But as we are here perhaps open to the reply, such 

 as it is, that the grilse may nevertheless be a dis- 

 tinct species, its narrower range of size being accounted 

 for by its being in its adult stage a much smaller fish, 

 we go on to the second point, and ask. Where are the 

 salmon when they are of the weight of, say, 4i or (3 lbs. ? 

 That salmon of such weights are often got, is true ; but 

 it is also true that, in proportion to the whole number, 

 that is the weight at which by far the fewest are got — 

 especially that many more are got much above than at 

 or about those weights. There are fewest salmon of the 

 weight of which there are most grilses. Now, as at some 

 time or another every salmon must be of those weights, 

 the presumption is that we ought to see many more of 

 them than of the higher weights, which, in the main, 

 signifies the greater ages— in short, if Mr. Mackenzie's 

 theory were correct, we ought to see more salmon of 

 those small sizes than of the large sizes, just as in our 

 own species we see more youths than elderly people. 

 Those youthful salmon do undoubtedly exist. Mr. 

 Mackenzie, if he hold to his theory, cannot tell us 

 where they are. We point to the grilse, and say, there 

 they are. 



On the point of appearance, Mr. Mackenzie possesses 

 whatever advantage or disadvantage there is in the fact 



