122 
DARWINISM 
CHAP. 
that of Danvin or as supplementary to it. Before doing this, 
however, it will be well briefly to summarise the facts and 
arguments already set forth, because it is only by a clear 
comprehension of these that the full importance of the theory 
can be appreciated and its further applications understood. 
The theory itself is exceedingly simple, and the facts on 
which it rests—though excessively numerous individually, and 
coextensive with the entire organic world—yet come under a 
few simple and easily understood classes. These facts are,— 
first, the enormous powers of increase in geometrical progres¬ 
sion possessed by all organisms, and the inevitable struggle for 
existence among them ; and, in the second place, the occurrence 
of much individual variation combined with the hereditary 
transmission of such variations. From these two great classes 
of facts, which are universal and indisputable, there necessarily 
arises, as Darwin termed it, the “ preservation of favoured races 
in the struggle for life,” the continuous action of which, under 
the ever-changing conditions both of the inorganic and organic 
universe, necessarily leads to the formation or development of 
new species. 
But, although this general statement is complete and indis¬ 
putable, yet to see its applications under all the complex 
conditions that actually occur in nature, it is necessary always 
to bear in mind the tremendous power and universality of the 
agencies at work. We must never for an instant lose sight 
of the fact of the enormously rapid increase of all organisms, 
which has been illustrated by actual cases, given in our second 
chapter, no less than by calculations of the results of un¬ 
checked increase for a few years. Then, never forgetting 
that the animal and plant population of any country is, on 
the whole, stationary, we must be always trying to realise the 
ever-recurring destruction of the enormous annual increase, 
and asking ourselves what determines, in each individual case, 
the death of the many, the survival of the few. We must 
think over all the causes of destruction to each organism,—to 
the seed, the young shoot, the growing plant, the full-grown 
tree, or shrub, or herb, and again the fruit and seed ; and among 
animals, to the egg or new-born young, to the youthful, and 
to the adults. Then, we must always bear in mind that what 
goes on in the case of the individual or family group we may 
