Conclusion 263 
been increased and modified by continual accession from 
without till they modify the molecular disturbances of the 
nervous system, and therefore its material substance, 
which we have already settled to be only our way of docket- 
ing molecular disturbances. The same vibrations, there- 
fore, form the substance remembered, introduce an infini- 
tesimal dose of it within the brain, modify the substance 
remembering, and, in the course of time, create and 
further modify the mechanism of both the sensory and 
motor nerves. Thought and thing are one. 
I commend these two last speculations to the reader’s 
charitable consideration, as feeling that I am here travelling 
beyond the ground on which I can safely venture ; never- 
theless, as it may be some time before I have another 
opportunity of coming before the public, I have thought it, 
on the whole, better not to omit them, but to give them thus 
provisionally. I believe they are both substantially true, 
but am by no means sure that I have expressed them either 
clearly or accurately ; I cannot, however, further delay the 
issue of my book. 
Returning to the point raised in my title, is luck, I 
would ask, or cunning, the more fitting matter to be insisted 
upon in connection with organic modification? Do 
anjmals and plants grow into conformity with their sur- 
roundings because they and their fathers and mothers take 
pains, or because their uncles and aunts go away ? For the 
survival of the fittest is only the non-survival or going 
away of the unfittest—in whose direct line the race is not 
continued, and who are therefore only uncles and aunts of 
the survivors. I can quite understand its being a good 
thing for any race that its uncles and aunts should go away, 
but I do not believe the accumulation of lucky accidents 
could result in an eye, no matter how many uncles and 
aunts may have gone away during how many generations. 
I would ask the reader to bear in mind the views concern- 
ing life and death expressed in an early chapter. They 
