192 BRITISH FRESH-WATER FISHES 
doctrine. No advance in knowledge is possible on such lines, 
which, on the contrary, must tend to the darkening of 
understanding. 
Those who hold to the belief that salmon feed in our 
rivers should reflect upon the depleted state of the salmon 
population. Industrious netting has brought the stock to 
a low ebb; were the fish as numerous now as they were 
in primitive times—as they are now in some of the rivers 
of the Pacific coast of America—what prospect would they 
have of subsistence in a hungry Highland river, where even 
the common trout display evidence of very meagre fare? 
Last year, during the great drought of July (1901), I lay 
on the rocks beside a deep but narrow “linn’’ on a Scottish 
river, and counted upwards of sixty salmon and grilse 
congregated there. The water was crystal clear; I could 
detect every movement of the fish, and specially took note 
of the action in performing a leap, as from time to time 
a fish would throw himself out of the water. Presently I 
noticed a couple of very small trout swimming unconcernedly 
over the backs of the great fish below, snapping at flies, 
and manifesting a sense of the utmost security. “My 
little friends!” was my soliloquy, ‘a sorry look-out it 
would be for you if salmon sought for food in fresh water.” 
No: it is contrary to the lessons of dispassionate 
observation, to common sense, and to the results of 
physiological research, to doubt that the normal condition 
of salmon, after they leave the sea and until they return 
to it, is one of fasting. The predaceous instinct and habit 
disposes them to seize, at capricious intervals, lifelike moving 
objects, such as artificial flies or spinning baits ; spasms of 
gourmandise induce them, also at capricious intervals, to 
seize and mumble such savoury morsels as worms or prawns ; 
but never has any man beheld salmon in quest of prey in 
a river. 
The case of the Canadian ouananiche and of the “ land- 
