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209 
Finally arises the consideration of what benefit to mankind 
in general are investigations into the breeding of fishes ? 
Here I shall merely enter upon a few, some being now carried 
out successfully, some experimentally, and, lastly, some theo- 
_ retically suggested. 
In a state of nature salmon and trout eggs are subject to 
_ destruction from many foes, and it has been computed that 
: although each female is provided with many hundreds of ova, 
_ only about one in nineteen of such as are left in the natural 
_redds ever hatch, and only four or five of these out of 30,000 
eggs arrive at maturity and are fit for the table; whereas, 
_ taking Howietoun as an instance, it is found that from 90 to 95 
per cent. hatch in a well-constructed fish cultural establishment, 
_ while the loss among the fry is inconsiderable. Irrespective of 
this, the young can be turned into the rivers at times when 
_ they would be more able to shift for themselves than if they 
_ resided there from their earliest days. 
Without entering into the reasons, still it is patent ta the 
most casual observer that the interests of the upper riparian 
proprietors of salmon rivers are not always in agreement with 
_ those of the estuaries and lower waters. The former consider 
the fish are reared in their territory, but that the produce is 
almost exclusively captured at or near the mouths of the rivers. 
The lower proprietors in some places, believing that the upper 
_ proprietors are helpless, do not always listen to their complaints | 
in an amicable manner, considering themselves masters of the 
‘situation. But as a knowledge of fish culture extends, it will 
be found that, did they know it, exactly the reverse is the case. 
The upper proprietors might obtain such splendid breeds of 
trout for their rivers that they would not care to continue 
preserving the salmon. Or they might introduce a land-locked 
salmon, or one which does not descend to the sea, but passes 
all its life in fresh water. Or hybrids between the salmon and 
trout might be sterile, and not take on migratory propensities. 
I have shown how, by selection of parents, larger and more 
‘rapidly growing trout can be raised, and these fish, provided 
they can obtain sufficient food, attain to a size now but seldom 
‘seen, but when observed being termed Salmo ferox. Thus eggs 
