How to obtain it. 285 
this is just why I wish to give a note of warning to those about to 
enter upon the work. ‘Do nothing rashly” is a motto that it 
would be well to observe in time. Nature provides for every- 
thing ; not one little bit of mechanism is wanting, and we find the 
result perfect. Take the flowers of the field or the fish of the sea 
as examples. Any one of them is perfect in itself. It remains 
so, and from generation to generation there is no perceptible 
difference in a species, be it what it may. But Nature makes 
special provision for this being so, and unless we do the same, 
confusion will be the inevitable result. 
It is true that we find monstrosities and malformations in the 
natural world ; it is according to the laws by which it is governed 
that it should be so.. But we only find them perpetuated under 
special and peculiar circumstances—they may be called isolated ' 
cases. Take, for instance, the tail-less trout of Islay, or the 
hunchbacks of Plinlimmon, to both of which reference has already 
been made. These are cases of fish living in pieces of enclosed 
water where they are very much separated from the rest of their 
species, and this probably accounts for the apparent discrepancies, 
if they be rightly so called, but they end there—they can get no 
further. We find, then, that Nature provides for such dis- 
crepancies, by arranging barriers beyond which they must not 
pass; and, if we take the trouble to investigate, we find that 
provision is made for preventing them from spreading, and for the 
preservation of a perfect race or type of fish. Nature, indeed, 
goes in for the selection of the fittest. . 
This, then, is what we ought to aim at in our work of cul- 
tivating fish of any kind, viz., the preservation of a perfect race or 
type. In order to do it, it is clear that we must take some pains 
to secure the best breeders. Having advanced so far, we have 
the power given to us of still further improving the stock by 
judicious crossing of the fish of different rivers. There is a large 
field open for investigation here. We know the great advantage 
of having good breeders amongst trout, and also of introducing 
new blood, and there is no reason for supposing that salmon 
should be made any exception to the rule which applies in such a 
marked degree to trout. 
Let,us turn our attention again for a few moments to those 
