COX ON THE FOUNDER OF THE EVOLUTION THEORY 233 
altogether probable that by an “acquired character” he meant merely any 
new character brought into existence in adaptation to a new demand made 
upon an animal by a change in its environment. Neither he nor Darwin 
knew of the fine distinctions now made between a quality inherent in the 
germ-plasm and a characteristic originating in the soma. Darwin, how¬ 
ever, conceived of two kinds of variation, the one the result of conditions 
acting “directly on the whole organization or on certain parts alone,” and 
the other due to influences indirectly affecting the reproductive system. 1 
He was also aware of Weismann’s earlier and less specific objections to the 
inheritance of characteristics acquired through the soma, but does not seem 
to have accorded them great weight, since he argues strongly for the heredi¬ 
tary transmission of the effects of changed habits in both animals and plants. 
He naturally did not like to exclude all such effects from the evolutionary 
process, for he held that “a variation which is not inherited throws no light 
on the derivation of species.” 2 He says: “When a new character arises, 
whatever its nature may be, it generally tends to be inherited, at least in a 
temporary and sometimes in a most persistent manner.” 3 A little later he 
expresses the conclusion that “the real subject of surprise is, as Sir H. 
Holland has well remarked, not that a character should be inherited, but 
that any should ever fail to be inherited.” 4 5 
With reference to the conception of a species as a elassificatory group, 
possibly Lamarck was somewhat more definite than Darwin, for Lamarck 
did propound a definition of species which is considered a good one, while 
Darwin carefully avoided making such a definition. It is truly remarkable, 
— and it is no disparagement of Darwin to concede it — that he who did more 
than all others to elucidate the whole subject of the origin, modification and 
transmutation of species should have felt himself unable to designate pre¬ 
cisely the subject of his inquiries. Writing to Joseph D. Hooker, in Decem¬ 
ber, 1856, he said: “It is really laughable to see what different ideas are 
prominent in various naturalists’ minds when they speak of ‘species’; in 
some, resemblance is everything and descent of little weight; — in some, 
resemblance seems to go for nothing and Creation the reigning idea,— in 
some, descent is the key,— in some, sterility an unfailing test, with others 
it is not worth a farthing. It all comes, I believe, from trying to define the 
undefmable.” 0 In an earlier letter in the same year, referring to his work 
on the Cirripedes, he wrote: “I know in my own case my most frequent 
source of doubt was whether others would not think this or that was a God- 
1 “Origin of Species,” 6th ed., p. 5. 1882. 
2 “Animals and Plants Under Domestication,” 1st ed., Vol. II, p. 1. 1S68. 
3 Ibid., p. 2. 
4 Ibid., p. 2. 
5 “Life and Letters,” Vol. II, p. 88. 1887. 
