THE LOCH PROBLEM 193 
however, that so far no sea-trout larger than 2 lb. 
have been caught in this loch. 
To summarise the results of these experi- 
ments, it seems clear that in order to obtain the 
best results the following conditions should be 
fulfilled : 
1 . There must be a sufficient supply of the right 
kind of food for the fish in the loch in order that 
they may grow to a large size. 
In order to attain this object, it is desirable 
that the loch should not be too high above the 
level of the sea. As Mr. Malloch says in the work 
to which I have already referred (p. 179) : " Lochs 
over 1000 feet above sea-level, fed from snow from 
surrounding hills, produce little feeding until May, 
and owing to the cold fall off in September, thus 
giving the trout only four months of good feed- 
ing. On the other hand, lochs at or near sea-level 
produce good feeding in March, and continue to 
do so for three months more than their Highland 
brethren. It will be seen, then, that this extra 
time for feeding, when extended over the seven 
or eight years which constitute the life of a trout, 
easily accounts for the difference of size." More- 
over, as the same writer points out, in a loch 
which is very high above the sea-level, not only 
25 
