[199] Philosophie zoologique, p. 56.
[200] Loc. cit., i., p. 113.
[201] Loc. cit., i., p. 361.
[202] Loc. cit., ii., p. 465.
[203] Système analytique des Connaissances de l’Homme, etc.
CHAPTER XX
THE RELATIONS BETWEEN LAMARCKISM AND DARWINISM; NEOLAMARCKISM
Since the appearance of Darwin’s Origin of Species, and after the great naturalist had converted the world to a belief in the general doctrine of evolution, there has arisen in the minds of many working naturalists a conviction that natural selection, or Darwinism as such, is only one of other evolutionary factors; while there are some who entirely reject the selective principle. Darwin, moreover, assumed a tendency to fortuitous variation, and did not attempt to explain its cause. Fully persuaded that he had discovered the most efficient and practically sole cause of the origin of species, he carried the doctrine to its extreme limits, and after over twenty years of observation and experiment along this single line, pushing entirely aside the Erasmus-Darwin and Lamarckian factors of change of environment, though occasionally acknowledging the value of use and disuse, he triumphantly broke over all opposition, and lived to see his doctrine generally accepted. He had besides the support of some of the strongest men in science: Wallace in a twin paper advocated the same views; Spencer, Lyell, Huxley, Hooker, Haeckel, Bates, Semper, Wyman, Gray, Leidy, and other representative men more or less endorsed Darwin’s views, or at least some form of evolution, and owing largely to their efforts in scientific circles and in the popular press, the doctrine of descent rapidly permeated every avenue of thought and became generally accepted.
Meanwhile, the general doctrine of evolution thus proved, and the “survival of the fittest” an accomplished fact, the next step was to ascertain “how,” as Cope asked, “the fittest originated?” It was felt by some that natural selection alone was not adequate to explain the first steps in the origin of genera, families, orders, classes, and branches or phyla. It was perceived by some that natural selection by itself was not a vera causa, an efficient agent, but was passive, and rather expressed the results of the operations of a series of factors. The transforming should naturally precede the action of the selective agencies.
We were, then, in our quest for the factors of organic evolution, obliged to fall back on the action of the physico-chemical forces such as light, or its absence, heat, cold, change of climate; and the physiological agencies of food, or in other words on changes in the physical environment, as well as in the biological environment. Lamarck was the first one who, owing to his many years’ training in systematic botany and zoölogy, and his philosophic breadth, had stated more fully and authoritatively than any one else the results of changes in the action of the primary factors of evolution. Hence a return on the part of many in Europe, and especially in America, to Lamarckism or its modern form, Neolamarckism. Lamarck had already, so far as he could without a knowledge of modern morphology, embryology, cytology, and histology, suggested those fundamental principles of transformism on which rests the selective principle.