36 SALMONIA. [second day. 



of the body becomes more uniform, — pale olive above, 

 and bright silver below; and these qualities are always 

 connected with a small head, — or rather, an oval body, 

 and deep-red flesh. 



POIET. — May not the red spots be marks of disease 

 — a hectic kind of beauty ? for I observed in a very 

 thin and poor fish, and great-headed, that I caught 

 an hour ago, which had leeches sticking to it, a 

 number of red spots, and a long black back, and 

 black or bluish marks even on the belly. 



HAL. — I do not think red spots a symptom of 

 disease ; for I have seen fish in other rivers, and even 

 small fish in this river, in perfectly good season, with 

 red spots ; but the colours of fish are very capricious, 

 and depend upon causes which cannot be easily 

 defined. The colouring matter is not in the scales, 

 but in the surface of the skin immediately beneath 

 them, and is probably a secretion easily affected by 

 the health of the animal. I have known fish, from 

 some lakes in Ireland, mottled in a most singular 

 way, — their colour being like that of the tortoise ; the 

 nature of the water, exposure to the light, and proba- 

 bly the kind of food, produce these effects. I think 

 it possible, when trout feed much on hard substances, 

 such as larvae and their cases, and the ova of other 

 fish, they have more red spots, and redder fins. This 

 is the case with the gillaroo and the char, who feed 



