4 
DARWINISM 
CHAl*. 
universe as a system of growth and development, and it was 
argued that the various species of animals and plants had 
been produced in orderly succession from each other by the 
action of unknown laws of development aided by the action 
of external conditions. Although this work had a consider¬ 
able effect in influencing public opinion as to the extreme 
improbability of the doctrine of the independent “ special 
creation ” of each species, it had little effect upon natural¬ 
ists, because it made no attempt to grapple with the problem 
in detail, or to show in any single case how the allied species 
of a genus could have arisen, and have preserved their 
numerous slight and apparently purposeless differences from 
each other. No clue whatever was afforded to a law which 
should produce from any one species one or more slightly 
differing but yet permanently distinct species, nor was any 
reason given why such slight yet constant differences should 
exist at all. 
Scientific Opinion before Darwin. 
In order to show how little effect these writers had upon 
the public mind, I will quote a few passages from the 
writings of Sir Charles Lyell, as representing the opinions 
of the most advanced thinkers in the period immediately 
preceding that of Darwin’s work. When recapitulating the 
facts and arguments in favour of the invariability and 
permanence of species, he says : “ The entire variation from 
the original type which any given kind of change can pro¬ 
duce may usually be effected in a brief period of time, after 
which no further deviation can be obtained by continuing to 
alter the circumstances, though ever so gradually, indefinite 
divergence either in the way of improvement or deterioration 
being prevented, and the least possible excess beyond the 
defined limits being fatal to the existence of the individual.” 
In another place he maintains that “ varieties of some species 
may differ more than other species do from each other 
without shaking our confidence in the reality of species.” 
He further adduces certain facts in geology as being, in his 
opinion, “fatal to the theory of progressive development,” 
and he explains the fact that there are so often distinct 
species in countries of similar climate and vegetation by 
