498 THE MAKING OF THE * OKIGIN ' 
been presented in consecutive form, there was the constant 
probability that criticism on a single point could not know that 
it was already outflanked by a previous argument, developed 
elsewhere by the author, but not impressed on the critic in this 
particular connection. Thus replying to Hooker, who finds 
the changes effected by external conditions inconstant and 
unequal to modifying species, Darwin urges (November 11, 
1856) that the external conditions by themselves do very little 
in producing new species, except as causing mere variability 
upon which selection can work. He feels strongly that to make 
this clear, he ought to have sent Hooker a preliminary note 
on variation and its causes. 
In this connection it may be noted that even after the 
publication of the ' Origin ' Hooker continued to lay more stress 
on external conditions than did Darwin, who explains (May 29, 
1860) that he sees in almost every organism (though far more 
clearly in animals than in plants) adaptation, and this, except 
in rare instances, must, he thinks, be due to selection.^ 
Again (March 16, 1858) Darwin finds the reason for various 
difficulties raised by Hooker in the fact that probably he has 
not yet sufficiently explained his notions, and begs his friend to 
await the MS. deaUng with these points. So when he does send 
1 Thus, in March 1862, Hooker wrote to Bates : ' I am sure that with you 
as with me, the more you think the less occasion you will see for anything but 
time and natural selection to effect change ; and that this view is the simplest 
and clearest in the present state of science is one advantage, at any rate. 
Indeed, I think that it is, in the present state of the inquiry, the legitimate 
position to take up ; it is time enough to bother our heads with the secondary 
cause when there is some evidence of it or some demand for it — at present I 
do not see one or the other, and so feel inclined to renounce any other for the 
present.' Hereupon Darwin finds it ' curiously satisfactory ' to see him and Bates 
' believing more fully in Natural Selection than I think I even do myself ' ; but 
he startled Darwin in November with the frank confession that every single 
difference which we see might have occurred Avithout any selection, having got 
right round the subject and viewed it from an entirely opposite and new side. 
' I do and have always fully agreed,' is Darwin's answer, but under certain 
provisos, which in fact do not seem to occur. See M.L. i. 212, 199, and 223. 
[Henry Walter Bates (1825-92), the ' Naturalist on the Amazons.' His 
boyish zeal for entomology took fuUer shape under the inspiration of A. R. 
Wallace, with whom he set out in 1848 for these unharvested regions. Here he 
spent eleven years. His wide researches into the insect fauna and the problems 
of mimicry led him towards the theorj' of natural selection; and he became at 
once a staunch supporter of Darwin when he returned in 1859. From 1864 until 
his death he was Assistant Secretary to the Royal Geographical Society, and he 
was elected F.R.S. in 1881.] 
