100 Heredity and Variation in Modern Lights 
discovery, is not very onerous. The doctrine “que tout est au mieux” 
was therefore preached with fresh vigour, and examples of that 
illuminating principle were discovered with a facility that Pangloss 
himself might have envied, till at last even the spectators wearied of 
such dazzling performances. 
But in all seriousness, why should indefinite and unlimited 
variation have been regarded as a more probable account of the 
origin of Adaptation? Only, I think, because the obstacle was shifted 
one plane back, and so looked rather less prominent. The abundance 
of Adaptation, we all grant, is an immense, almost an unsurpassable 
difficulty in all non-Lamarckian views of Evolution ; but if the steps 
by which that adaptation arose were fortuitous, to imagine them 
insensible is assuredly no help. In one most important respect 
indeed, as has often been observed, it is a multiplication of troubles. 
For the smaller the steps, the less could Natural Selection act 
upon them. Definite variations—and of the occurrence of definite 
variations in abundance we have now the most convincing proof— 
have at least the obvious merit that they can make and often do 
make a real difference in the chances of life. 
There is another aspect of the Adaptation problem to which I 
can only allude very briefly. May not our present ideas of the 
universality and precision of Adaptation be greatly exaggerated ? 
The fit of organism to its environment is not after all so very close— 
a proposition unwelcome perhaps, but one which could be illustrated 
by very copious evidence. Natural Selection is stern, but she has 
her tolerant moods. 
We have now most certain and irrefragable proof that much 
definiteness exists in living things apart from Selection, and also much 
that may very well have been preserved and so in a sense constituted 
by Selection. Here the matter is likely to rest. There is a passage 
in the sixth edition of the Origin which has I think been overlooked. 
On page 70 Darwin says “The tuft of hair on the breast of the wild 
turkey-cock cannot be of any use, and it is doubtful whether it can 
be ornamental in the eyes of the female bird.” This tuft of hair is a 
most definite and unusual structure, and I am afraid that the remark 
that it “cannot be of any use” may have been made inadvertently ; 
but it may have been intended, for in the first edition the usual 
qualification was given and must therefore have been deliberately 
excised. Anyhow I should like to think that Darwin did throw over 
that tuft of hair, and that he felt relief when he had done so. 
Whether however we have his great authority for such a course or 
not, I feel quite sure that we shall be rightly interpreting the facts 
of nature if we cease to expect to find purposefulness wherever we 
meet with definite structures or patterns. Such things are, as often 
