Criticisms of Theory of Natural Selection. 363 
of emphasis, by the Duke of Argyll, Mr. Mivart, Pro- 
fessors Nageli, Bronn, Broca, Eimer, and, indeed, by all 
other writers who have hitherto advanced it. For, as 
thus presented, I think I have shown that it admits of 
being adequately met. But now, I must confess, to me 
individually it does appear that behind this erroneous 
presentation of the difficulty there lies another question, 
which is deserving of much more serious attention. 
For although it admits of being easily shown—as I have 
just shown—that the difficulty as ordinarily presented 
fails on account of its extravagance, the question 
remains whether, if stated with more moderation, a 
real difficulty might not be found to remain. 
My quarrel with the conclusion, like my quarrel 
with the premiss, is due to its universality. By say- 
ing in the premiss that a// incipient organs are meces- 
sarily useless at the time of their inception, these 
writers admit of being controverted by fact; and by 
saying in the conclusion that, zf all incipient organs 
are useless, it necessarily follows that in zo case can 
natural selection have been the cause of building up 
an organ until it becomes useful, they admit of being 
controverted by logic. For, even if the premiss were 
true in fact—namely, that all incipient organs are use- 
less at the time of their inception,—it would not 
necessarily follow that in no case could natural selec- 
tion build up a useless structure into a useful one; 
because, although it is true that in no case can natural 
selection do this by acting on a useless structure 
directly, it may do so by acting on the useless struc- 
ture zzdivectly, through its direct action on some other 
part of the organism with which the uscless structure - 
happens to be correlated. Moreover, as I believe, and 
