THE COMMON TROUT 263 



nation here is the likeliest namely, that in great and deep 

 lakes, fed by countless streams nourishing immense numbers 

 of small trout, all the trout would remain small, were it not 

 that some of their number, favoured by ample depth and 

 expanse of water and by their own superior energy, gradually 

 obtain some advantage, become so much larger than their 

 fellows, that, when pressed for food, they take to preying on 

 their own kind. For these so-called ferox have well earned 

 the title of ferocious, being habitual cannibals. The result is 

 to the advantage of the community, for it is to be noted that 

 in lakes fed by numerous streams affording unlimited spawning- 

 ground, trout will multiply up to the very limits of subsistence, 

 but all will remain insignificant in size, unless pike or ferox 

 are present to act as a check upon numbers, in which case the 

 average weight of the trout will be considerably greater, and 

 their quality better, through the reduction of the number of 

 mouths to feed. 



It may be observed, parenthetically, that it would be an 

 exceedingly rash proceeding to introduce pike into a lake 

 which is overstocked with small trout in order to increase their 

 size. The proper course to that end is to limit the spawning- 

 ground by erecting impassable barriers upon some of the 

 tributary streams, at the same time doing all that is possible to 

 improve the food supply. 



Before dismissing the so-called Salmo ferox as a mere 

 variant, full or overgrown, of the common trout, it is to be 

 noted that, as in all the rest of the species, much of the 

 external colour is exceedingly transient. Sometimes ferox 

 from 8 Ib. to 1 5 Ib. are grey and silvery when landed ; at 

 other times they are intensely dark, with numerous spots and 

 fiery .sparkles. But I have seen some of these dark monsters, 

 left in a cool place overnight, appear quite bright and salmon- 

 like in the morning. In fact, it is impossible to judge of the 

 permanent skin colour and markings of any trout unless it is 

 wrapped in a wet cloth and so left for some hours. 



