IISTLTJE^CE OF THE FOOD OF FISHES. 23 



empty : in the latter the flesh was paler, and the stomach and 

 intestines loaded with semi-putrescent debris. 



I have since made the same observation with respect to hir- 

 ling and sea trout taken in the Solway ; that is, that whenever 

 they have been living on the eggs of the Echinodermata, the 

 flesh was deep-coloured, and their stomach and intestines all but 

 empty; the opposite being the case when sand-eels and fry 

 formed their food. Thus food has a certain influence over the 

 quality of fish. The rich colour of the salmon, and the excellent 

 qualities of the flesh of the char, of the winter and spring trout 

 of Loch Leven, do not depend altogether upon the peculiar food 

 which it is now known* these fishes prefer ; but unquestionably 

 this food is necessary to bring them to that perfection in colour 

 and flavour which renders them so excellent. On the quality of 

 the food then, combined with other circumstances, will depend 

 the excellence of the fish ; that is, whether or not the individual 

 is to reach that perfection which we know to be attainable under 

 favourable circumstances. But to this must be added " specific 

 character" and "the appropriate season," without which no food 

 can ever avail. 



The flesh or muscle of the smolt (young salmon) is pale, and 

 not much better than a common trout of the same size. It 

 bears the same relation to the flesh of the grown fish, the adult 

 salmon, that veal does to prime beef. Its food, it is true, is the 

 food of the common river trout, on which, whilst in the fresh- 

 water streams, it feeds voraciously. But descending to the sea, 

 it in a very few months, nay, even weeks, rapidly attains matu- 

 rity. What in the meantime has happened ? 1st, it has grown, 

 and become matured ; 2nd, it has obtained in great abundance, 

 no doubt, the real food its instincts prompt it to feed on ; 3rd, 

 it breathes a marine air, as nature intended it should. 



The streams, then, which run from the Pentland range contain 

 the red-spotted pink-coloured trout, analogous, if not identical, 

 with that of England. The common red-spotted trout, coarse 

 and tasteless, is also there ; yet I mention it as somewhat 

 remarkable that, in as far as my experience goes, admirable trout, 



* Dr. Knox's "Memoirs on the Salmonidae. "Trans. Royal Soc. Edin. 



