NATURAL HISTORY OF BRITISH SALMONIDA. 141 
money value of about 160,000/, Unfortunately, however, the 
fry actually added to the stock of the river are a mere fraction, 
and those that survive to return as grilse a very trifling frac- 
tion of these numbers. The calculations that have been made 
vary from about one in every thousand, to one in every six 
thousand, out of the original deposit of ova,—a wholesale 
slaughter which might appear incredible if we did not realise 
how numerous are the causes of destruction, From the lay- 
ing of the egg until the plunge of the young smolt into the 
tidal wave, and even afterwards in the broader waters of the 
estuary or open sea, a hundred wholesale depredators lie in 
wait for it. 
First there are the shoals of hungry fish of all kinds which 
prowl about the fords, pressing close behind the spawner, and 
ready to fight for her eggs almost before they are laid; then 
come the voracious larvee of the may-fly and stone-fly, the 
water shrimps, and a host of kindred insects, which work their 
way in amongst the gravel and destroy, perhaps less ostenta- 
tiously, but not less certainly ; or a winter flood will sweep 
down the river, and bury a whole brood under a foot of sand 
drift. If the egg escapes these perils, and, in due course, 
releases its charge, fresh dangers await the delicate and im- 
mature fry. The trout, the heron, the wild duck—nay, even 
the parent salmon themselves—hunt it out in its sheltering 
creeks and crevices ; and hundreds of fry are daily sacrificed 
on a single spawning bed by this means. Lastly, as if these 
‘natural enemies’ were insufficient, comes the human parr- 
poacher, man and boy,—and the wonder is really not at the 
high rate of infant mortality amongst the Sa/monide, but 
rather at there being any survivors. The first sign of anima- 
tion in the ova, which have now been deposited and covered 
carefully up under little mounds of fine gravel, is the appear- 
ance of the eye, which may be noticed, a scarcely perceptible 
black speck, in from forty to sixty days after deposition. The 
eye gradually increases in size until the time of hatching—an 
event which usually occurs in from go to 140 days, according 
