THE COMMON TROUT 261 



as to appear creatures of totally distinct species. Fatio, 

 writing about the trouts of Central Europe, observes : " The 

 little brook-trout which most zoologists distinguish under the 

 name of Salmo Ausonii is truly, in my opinion, nothing more 

 than a form of the great trout of our lakes, which is called, 

 according to circumstances, 'Trutta lacustris, 'Trutta Schiffer 

 Miiiieri, Fario Marsiglii, or Salmo lemanus. Most of the 

 characters proposed for its distinction are those of the early 

 age of the fish. In a small stream the trout, which cannot 

 grow for want of room, arrives at an advanced age, retaining 

 more or less of the character of infancy," 



Even so in this country. Taking two lakes in Central 

 Scotland within four miles of each other in the forest of 

 Corrour — Loch Ossian, a little more than three miles long, 

 and Loch Treig, about seven miles long — we find the most 

 striking contrast in their trout population. No salmon or 

 migratory sea-trout obtain access to one or other. Loch 

 Ossian is comparatively shallow, and swarms with small trout 

 about six or eight to the pound. You may fill a barrow with 

 them by fly-fishing on a mild day, and never get one weighing 

 more than a quarter of a pound. Moreover, every fish retains 

 the juvenile parr-markings, and the flesh is white or lightly 

 tinged with pink. The food supply of the lake being a fixed 

 quantity, it has to be sub-divided among millions of mouths, 

 whence it comes that the trout of the lake are all dwarfs. It is 

 very difl'erent in Loch Treig, which is of immense depth — 

 one of the requisites indispensable to the production of that 

 class of trout which Dr. Giinther distinguishes as the Great 

 Lake Trout of North Britain, Wales, and Ireland {Salmo fer ox). 



Ferox of great size inhabit Loch Treig, and the rest of 

 the trout therein are goodly fish, running commonly from 

 -| lb. to 2 lb. I " say the rest of the trout " ; but who is to 

 declare which 2sq. ferox and which -dSQ. fario } Is it a question 

 of size } Then I ask the reader to what species does he assign 

 the great silvery trout of the Thames, running up to 12 lb. 



