ON VARIATION GENERALLY. 
19 
wHcli lielp existence under the altered conditions will mani- 
festly be fostered, and tend to accumulate, because the indi- 
viduals so favoured have a better chance of longer life and 
more numerous offspring. For instance — in order to keep to 
our subject — if a number of Ferns be transported to a warmer 
or colder climate than is natural to them, in the first place, 
only those survive which are best fitted to stand the change, 
and in the succeeding generations, all those of their offspring 
whose constitutions vary ever so little in the right direction 
will grow stronger, scatter more spores, and transmit their 
greater strength continually, until, in course of time, the 
balance will be restored, and a tribe of Ferns of a different 
constitution, and, what is more to the point, of distinctly 
different appearance, will be found to exist. 
This is Nature’s general method, which is a slow and 
mercilessly extravagant one. But if we bring man upon the 
scene, with his selective and protective power, the process is 
enormously accelerated; and, practically, he can do as much 
in the way of re-modelling a cow, a dog, a pigeon, a flower, 
or even a Fern, in his own lifetime, as Nature, left alone, 
would accomplish in thousands of years. This re-modelling 
is effected by the constant selection by the breeder, or horti- 
culturist, or Fern-lover, of the types nearest to his ideal one, 
and the rejection of all others, the result, in most cases, being 
eventually the production of a breed or strain possessing 
exactly the points aimed at. 
This is usually the accumulated result of many small differ- 
ences, but not always. Nature every now and again takes, 
as it were, a jump, the offspring of both animals and plants 
being sometimes extremely different from the parents, new 
breeds and strains thus originating which would otherwise 
never have been dreamt of, and which, it may be remarked, 
are not always capable of long survival in the struggle for 
existence, their eccentricity being against them, and not in 
their favour; or, as we have said, it may be obliterated by 
crossing with the common form. Ferns, especially, seem gifted 
with this power of producing dissimilar offspring, since many 
of the more marked and extraordinary forms have been found 
c 2 
