BIRDS OF PREY. 17 
mouse, the cockchafer, and the wireworm, may be 
specially instanced as seriously affecting by their ravages 
both the corn crops and young plantations; but remove 
the checks which keep them within the bounds designed 
by their all-wise Creator, and they rapidly increase, the 
damages they commit being multiplied immensely, and 
possess a money value which few who have not examined 
into the matter, would calculate upon. Instead, there- 
fore, of a supposed gain being derived from a practice, 
which I fear is too prevalent, an actual loss is the 
general, and I believe inevitable, result. 
This subject was incidentally alluded to by Sir William 
Jardine at the meeting of the British Association in 
1856, in connexion with the artificial propagation of 
salmon in the Tay, a subject on which he was specially 
deputed by his section to report. In the course of his 
remarks, he stated that it had been found that one of 
the worst enemies of the salmon ova in the breeding 
beds was the larva of the Mayfly, which, in its turn, was 
a favourite food of the trout. Now the practice in rivers 
preserved for salmon-fishing was to destroy trout, while 
this fact clearly showed that such ought not to be the 
case, as, by keeping down the Mayfly, they aided in 
propagating the salmon. As an illustration of this 
immutable law of nature, Sir William pointed out that 
in parts of the country where hawks had been ruthlessly 
extirpated, with the object of encouraging the breed of 
game, woodpigeons had increased to such an extent as 
to have become a positive nuisance, and most injurious 
to the farmer; and he showed tle danger incurred by 
unduly interfering with the balance established by 
nature amongst wild animals. But I shall recur to this 
point again. 
Cc 
