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Page:Popular Science Monthly Volume 65.djvu/249

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245
EIGHTEENTH CENTURY EVOLUTIONISTS.

processes of nature in the production of animals and the conservation of them.' The general processes which Maupertuis thought it especially important that zoological science should investigate are those through which animal individuals and species have come to have the differences of form and function that distinguish them. Maupertuis, in a word, appears to have clearly envisaged the genetic problem in biology, at a period in the history of thought when genetic problems generally were little considered. The center of interest in zoology therefore lay, for him, in the problems of embryogeny and of heredity. Although not himself an anatomist, he made himself familiar with investigations made by others on the minute anatomy of the embryo. And, as I have intimated, he never tired of insisting that the facts of heredity should be investigated, in the case of animals, by experiments in the interbreeding of species and varieties, and, in the case of human beings, by a collation of family histories.

The opinions of Maupertuis on these matters are expressed chiefly in the work called 'Vénus Physique' (1745) and in the 'Système de la Nature' (1751). The latter first appeared in the form of a Latin dissertation ostensibly delivered at Erlangen by one Dr. Baumann. Maupertuis found it expedient thus to shelter himself against reproach on account of any heterodox tendencies that the book might be found to contain. Four editions—all but the first in French—were called for within four years, and the author soon assumed responsibility for his work. In the 'Vénus Physique' Maupertuis essayed the popular style, and the book is consequently marred by passages written in an abominably rhetorical and affected manner. But, none the less, it constitutes, if I am not mistaken, the first important attack made in the eighteenth century upon the theory of the preformation of the embryo. Harvey had advanced the doctrine of epigenesis nearly a century earlier, but his arguments had failed to convince his successors, and his observations upon the chick had been shown by Malpighi to be partially erroneous.[1] At the time when Maupertuis wrote, preformationism had long been the ruling doctrine in embryology; an immense weight of scientific authority was in its favor. Among the philosophers Malebranche and Leibniz had argued for it, among the great physiologists and anatomists Swammerdam, Redi, Malpighi, Leeuwenhoek, Winslow and Haller had taught it. Bonnet was yet to give it its most elaborate exposition and defense; and three quarters of a century later it was still to find an adherent in Cuvier. The 'Vénus Physique' is a review of the preformation theory in its several forms, designed to show that the evidence against it is conclusive.

Of the arguments for epigenesis which Maupertuis offers it is not possible, in this brief paper, to give any sufficient account. He relies in part upon the observations of Harvey—and in so doing shows himself


  1. 'De formatione pulli in ovo,' 1673; 'De ovo incubato,' 1686.