ON THE LATEST FORM OF THE DEVELOPMENT THEORY. 108 
but on the exceptions, the accidents. Their whole proceeding is an attempt to estab- 
lish a philosophy of nature, or a theory of creation, on anomalies, — on rare accidents, 
— on lusus nature. i 
This single objection is fatal to Mr. Darwin’s theory, which depends on the accumu- 
lation, one upon another, of many successive instances of departure from the primitive 
type. For if even Individual Variation appears only in one case out of a hundred, — 
and all naturalists will admit this proportion to be as large as the facts will warrant, — 
and if, out of the cases in which it does appear, not more than one in a hundred is 
perpetuated by inheritance, then should a second Variation happen, what chance has it 
of leaping upon the back of one of the former class? The chance is one out of 100 
X 100 x 100 = 1,000,000. And the chance of a third Variation being added to a 
second, which in turn has been cumulated upon a first, will be one out of 100 raised 
to the fourth power, or 100,000,000. It is not necessary to carry the computation any 
further, especially as Mr. Darwin states (page 90) that the process of development can 
be carried out * only by the preservation and accumulation of infinitesimally small in- 
herited modifications." Of course, the interval between two Species so distinct that 
they will not interbreed could be bridged over only by a vast number of modifications 
thus minute; ànd on this calculation of the chances, the time required for the devel- 
opment of one of these Species out of the other would lack no characteristic of eternity - 
except its name. But the theory requires us to believe that this process has been re- 
peated an indefinite number of times, so as to account for the development of all the 
Species now in being, and of all which have become extinct, out of four or five primeval 
forms. If the indications from analogy, on which the whole speculation is based, are 
so faint that the work cannot have been completed except in an infinite lapse of years, 
these indications practically amount to nothing. The evidence eager needs to be 
multiplied by infinity before it will produce conviction, is no evidence at all. o 
4. What is here called the * Struggle for Life” is only another uano for the pus 
fact, that every Species of animal and vegetable life has its own Conditions of Existence, 
on which its continuance and its relative numbers depend. Remove any one of these 
Conditions, and the whole Species must perish ; abridge any of them, and the = 
of individuals in the Species must be lessened. The intrusion of a new race widok is 
more prolific, more powerful, more hardy, or in any —— gc the senti 
ay gradually crowd out some of its predecessors, or restrict them within comparatively 
bi bounds. Thus the introduction of the Norway rat has banished the former 
familiar plague of our households and barns from many of its old haunts, and probably 
reduced the whole number in this Species to a mere fraction of what it once was. 
