APPENDIX. 177 



M. Do grilse spawn by themselves, and in rivers, as salmon 

 do? 



H. I have already hinted at the difference of instinct between 

 salmon and grilse, by making one a spring and the other a 

 summer fish, although in their habits they are precisely the 

 same, each coming to the rivers and ascending them as far as 

 they can, and there depositing their spawn precisely as the 

 salmon do, at the same time keeping distinct from them as a 

 separate family. The only way to arrive at the truth is to 

 watch the burns and discover the bed of one pair only where 

 they would be easily captured, which would set the matter at 

 rest. This, to my knowledge, has been frequently done, and 

 uniformly resulted in the same fact — viz. either two salmon 

 were found together, or two grilse, which is very different from 

 the vague statements of those who profess to arrive at conclu- 

 sions from seeing a number of fish spawning on fords in large 

 rivers, or capturing one fish with the leister, the fellow escap- 

 ing in the crowd of other fishes. 



M. Why is it that people assert that salmon spawn with 

 grilse or with trout, and that they do not make a fuss about 

 the operations of sea fishes and land animals? 



H. Therein consists the absurdity of theorising without con- 

 sulting nature at all. If you look to the different tribes of 

 animals, birds, and fishes, you will find that each family ad- 

 heres strictly to its own members, and never intermixes with 

 the tribe. For instance, a sparrowhawk keeps itself distinct 

 from the gosshawk, the gosshawk from the harrier, the har- 

 rier from the gled, the gled from the osprey, and the osprey 

 from the golden eagle. In like manner, the innumerable 

 branches of the families of antelopes observe the laws of nature, 

 keeping separate and distinct, and thereby perpetuating the 

 different kinds without ever running into an heterogeneous 

 amalgamation. The same law applies to fishes. Yet were all 

 these varieties of the hawk first seen by a person ignorant of 

 their nature and habits, he would very likely, as people do 

 regarding salmon and its many varieties, pronounce the spar- 

 rowhawk a young eagle, a rook a young raven, or a grilse a 

 young salmon. 



M 



