Buffon erred rather on the side of ignoring functionally produced modifications than of insisting on them. The main agency with him is the direct action of the environment upon the organism. This, no doubt, is a flaw in Buffon’s immortal work, but it is one which Erasmus Darwin and Lamarck easily corrected; nor can we doubt that Buffon would have readily accepted their amendment if it had been suggested to him. Buffon did infinitely more in the way of discovering and establishing the theory of descent with modification than any one has ever done either before or since. He was too much occupied with proving the fact of evolution at all, to dwell as fully as might have been wished upon the details of the process whereby the amœba had become man, but we have already seen that he regarded inherited mutilation as the cause of establishing a new breed of dogs, and this is at any rate not laying much stress on functionally produced modifications. Again, when writing of the dog, he speaks of variations arising “_by some chance_ common enough with nature,” { 104a} and clearly does not contemplate function as the sole cause of modification. Practically, though I grant I should be less able to quote passages in support of my opinion than I quite like, I do not doubt that his position was much the same as that of his successors, Erasmus Darwin and Lamarck.
Lamarck is more vulnerable than either Erasmus Darwin or Buffon on the score of unwillingness to assign its full share to mere chance, but I do not for a moment believe his comparative reticence to have been caused by failure to see that the chapter of accidents is a fateful one. He saw that the cunning or functional side had been too much lost sight of, and therefore insisted on it, but he did not mean to say that there is no such thing as luck. “Let us suppose,” he says, “that a grass growing in a low-lying meadow, gets carried _by some accident_ to the brow of a neighbouring hill, where the soil is still damp enough for the plant to be able to exist.” { 105a} Or again—“With sufficient time, favourable conditions of life, successive changes in the condition of the globe, and the power of new surroundings and habits to modify the organs of living bodies, all animal and vegetable forms have been imperceptibly rendered such as we now see them.” { 105b} Who can doubt that accident is here regarded as a potent factor of evolution, as well as the design that is involved in the supposition that modification is, in the main, functionally induced? Again he writes, “As regards the circumstances that give rise to variation, the principal are climatic changes, different temperatures of any of a creature’s environments, differences of abode, of habit, of the most frequent actions, and lastly of the means of obtaining food, self-defence, reproduction,” &c. { 105c} I will not dwell on the small inconsistencies which may be found in the passages quoted above; the reader will doubtless see them, and will also doubtless see that in spite of them there can be no doubt that Lamarck, while believing modification to be effected mainly by the survival in the struggle for existence of modifications which had been induced functionally, would not have hesitated to admit the survival of favourable variations due to mere accident as also a potent factor in inducing the results we see around us.