THE COMMON BROWN TROUT. 217 



they are common," he adds. He also gives particulars of an extra- 

 ordinary distortion or deficiency in the trout found in Malham Tarn, 

 Yorkshire, specimens of which he obtained from Mr. Morrison, M.P. 

 The situation of the water is 1200ft. above the level of the sea ; the 

 strata is limestone, and the water clear. The fish are called silver trout, 

 from their appearance ; and there is another species in the same water, 

 which he does not doubt to be the lake trout (S. ferox), of which the 

 colour is yellow. This silver trout is of the ordinary size of its species, 

 and fairly well conditioned, and the peculiarity consists in the absence 

 of the opercula on either one or the other sides of the head, sometimes, 

 indeed, on both, so that the branchia or gills are open to the water and 

 unprotected. He remarks that about four or five trout were caught 

 exhibiting this peculiarity, and these did not seem to have suffered any 

 inconvenience. Yarrell speaks also of a trout having a separate head 

 and tail, and Thompson, in the " Natural History of Ireland," mentions 

 other malformations and similar ones to those already referred to. 



It may, indeed, be said that the salmonidae are more liable to mon- 

 strosities than any other fish, and trout are the most liable of the 

 salmonidae. 



It is quite as well that the angler should be able to distinguish the 

 male from the female trout, and for this purpose I give the following 

 particulars. In the male the head in front of the eyes is always more 

 lengthened than in the female, giving the fish an unfailing appearance 

 of superior size in that part of the body. Towards spawning, also, the 

 size of the abdomen sensibly increases, and the curve of the upper part 

 of the body is more pronounced in the female. A little close observa- 

 tion of the unnameable peculiarities which exist to render the appear- 

 ance of the sexes different will soon enable the angler to pronounce with 

 celerity and certainty on the sex of any fish brought before him. 



The range of habitat of the trout, like that of the rest of the 

 salmonidas, is very wide. Within a certain range of temperature its 

 acclimatisation, if it does not already exist, is certain of success, and its 

 growth and multiplication sure. Sir J. Malcolm found it in a stream of 

 a mountain in Persia, and Heber observed it amongst the Himalayas. 

 On the other hand, Parry found it existing in a lake in Melville Island, 

 where the temperature falls many degrees below zero. It is well known 

 that it now exists in comparative plenty at the Antipodes. 



The food of trout is of great variety, and consists chiefly of insects 

 and worms. The fish is not herbivorous, it is considered, and with 

 considerable show of reason, that the blood or vital fluid of much of its 

 insectivorous prey may go far to account for some of its peculiarities 

 of colouring. The plausibility of this lies in the fact that the juices of 



