190 AMID THE HIGH HILLS 
P. D. Malloch, who says in his well-known work 
on the Life History and Habits of the Salmon, 
Sea-trout, Trout and other Fresh-water Fish ^ 
(p. 186) : "When a farmer rents a piece of land 
for grazing he knows how many sheep or cattle it 
wiU pasture, and that if he puts on more than the 
proper number they will not grow. He also 
knows that if he introduce too few they will 
become fat and too lazy to eat up all the pasture, 
and he will thus lose part of the money paid for 
the pasture land. If the proprietor or the tenant 
of a loch would consider the matter in the same 
way as the farmer, he would obtain full value out 
of his lochs, be saved a deal of grumbling, and 
find life more pleasant." The same writer also 
says (p. 157) : " Many naturalists maintain that 
there are different species of trout in the British 
Islands — Loch Leven trout, Gillaroo trout, tidal 
trout, and many others — but from a close study of 
all these trout for the last forty years, I have come 
to the conclusion that there is only one species 
of trout in Great Britain, and that in the different 
varieties the differences are caused by the nature 
of the water in which they are found and by the 
food they eat." Thus, as would be expected, 
1 Adam & Charles Black, London, 1910. 
