Evolution, Old & New / Or, the Theories of Buffon, Dr. Erasmus Darwin and Lamarck, / as compared with that of Charles Darwin

by Samuel Butler

"'Habit,' says the proverb, 'is a second nature'; what possible meaning can this proverb have, if descent with modification is unfounded?[291]

"As regards the circumstances which 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., &c."[292]

Here we have absolute agreement with Dr. Erasmus Darwin,[293] except that there seems a tendency in this passage to assign more effect to the direct action of conditions than is common with Lamarck. He seems to be mixing Buffon and Dr. Darwin.

"In consequence of change in any of these respects, the faculties of an animal become extended and enlarged by use: they become diversified through the long continuance of the new habits, until little by little their whole structure and nature, as well as the organs originally affected, participate in the effects of all these influences, and are modified to an extent which is capable of transmission to offspring."[294]

This sentence alone would be sufficient to show that Lamarck was as much alive as Buffon and Dr. Darwin were before him, to the fact that one of the most important conditions of an animal's life, is the relation in which it stands to the other inhabitants of the same neighbourhood—from which the survival of the fittest follows as a self-evident proposition. Nothing, therefore, can be more unfounded than the attempt, so frequently made by writers who have not read Lamarck, or who think others may be trusted not to do so, to represent him as maintaining something perfectly different from what is maintained by modern writers on evolution. The difference, in so far as there is any difference, is one of detail only. Lamarck would not have hesitated to admit, that, if animals are modified in a direction which is favourable to them, they will have a better chance of surviving and transmitting their favourable modifications. In like manner, our modern evolutionists should allow that animals are modified not because they subsequently survive, but because they have done this or that which has led to their modification, and hence to their surviving.

Having established that animals and plants are capable of being materially changed in the course of a few generations, Lamarck proceeds to show that their modification is due to changed distribution of the use and disuse of their organs at any given time.

"The disuse of an organ," he writes, "if it becomes constant in consequence of new habits, gradually reduces the organ, and leads finally to its disappearance."[295]

"Thus whales have lost their teeth, though teeth are still found in the embryo. So, again, M. Geoffroy has discovered in birds the groove where teeth were formerly placed. The ant-eater, which belongs to a genus that has long relinquished the habit of masticating its food, is as toothless as the whale."[296]

Then are adduced further examples of rudimentary organs, which will be given in another place, and need not be repeated here. Speaking of the fact, however, that serpents have no legs, though they are higher in the scale of life than the batrachians, Lamarck attributes this "to the continued habit of trying to squeeze through very narrow places, where four feet would be in the way, and would be very little good to them, inasmuch as more than four would be wanted in order to turn bodies that were already so much elongated."[297]

If it be asked why, on Lamarck's theory, if serpents wanted more legs they could not have made them, the answer is that the attempt to do this would be to unsettle a question which had been already so long settled, that it would be impossible to reopen it. The animal must adapt itself to four legs, or must get rid of all or some of them if it does not like them; but it has stood so long committed to the theory that if there are to be legs at all, there are to be not more than four, that it is impossible for it now to see this matter in any other light.