502 Dr KNOX on the Natural History of 



text, or appendix, is intended to be addressed to persons whose education and habits of 

 thought are so low as not to observe, without its being pointed out to them, the amaz- 

 ing errors in point of fact, wideness of hypotheses, and abuse of what is called non se- 

 quiturs, in the above passage. 



In speaking of insects which attack salmon, Mr FRASER has omitted making any men- 

 tion of the internal parasitical animals, which we think he would have mentioned, had 

 he seen them, or seeing them, known their nature. I confess this excites strong doubts 

 in my mind as to the accuracy of Mr ERASER'S observations generally, and causes me to 

 undervalue altogether his forty years' experience as a salmon-curer. The reader, by 

 referring to the history of the evidence before the House of Commons, contained in this 

 Appendix, will there find that a practical fisherman and tacksman, who had paid thou- 

 sands a year, and that for many years, to river and sea proprietors, was so totally inr 

 competent to make any proper observations on the natural history of the salmon, that 

 he mistook the tape-worm for the food of the salmon. Mr ERASER'S remark, that he 

 has found the lernea upon " the gills of the breeding-salmon- on the return of the latter 

 to their rivers in the month of July or August," is peculiar to himself, and of course 

 would require some farther confirmation. Mr PHASER'S honesty and good faith induces 

 him to put credence in the experiments regarding the return of salmon to their own 

 rivers, and the growth of the smolt to the grilse within a certain time. Our remarks 

 on this point will be found in the text; the whole is perhaps more curious than imports 

 ant. It seems done with the view of proving the herling an adult fish when twelve 

 inches long, and thereby allowing the mesh of the net to be small ; but the natural his- 

 tory of the herling is not to be come at in this manner. 



As a proof of the extreme candour of Mr FRASER, I refer the reader to his chapter 

 on Great and Small Salmon. It will be there found that Mr FRASER has a mind capable 

 of rising above all prejudices in the pursuit of truth. 



The section containing Mr FRASER'S experiments on the Smolt, contains, without 

 doubt, a number of very curious observations. When Mr FRASER has repeated them 

 carefully, and noted a number of circumstances regarding them, which unfortunately 

 have been omitted, I shall be most happy to notice them more particularly : for the pre- 

 sent, I may remark, that they are very much at variance with what has been observed by 

 'Mr BUIST and myself. Mr FRASER thinks he has proved that ova may remain buried 

 to a depth of six or eight inches all summer, for at least four months, and at ten yards 

 distant from the river. 



The question of the fry getting early or late to the sea, is one which, of course, is not 

 easily settled. Mr FRASER thinks that fry live buried in sand and pebbles from 1st 

 April to 1 st August, and probably later, and without food, and that they do not grow- 

 larger in their native beds under such circumstances, than they do when confined, as 

 described above, in & dish of water, and he thinks it quite clear that it is these fry which 

 are buried in gravel all summer, that " partly supply us with clean and early salmon 

 every season." With reference to this I have just a single question to ask, and until 

 this be fairly answered, I should deem it unnecessary to notice these opinions further. 

 If fry thus ascend through the gravel, at various times, from the 1st April to 1st Au*- 

 gust, and probably later, ho.w comes it that they are not taken by. the angler after 

 May, or seen in small dams, weirs, &c. by the river side ? 



