DR. DRAPER'' S LECTURE ON EVOLUTION. 181 



condemned as morally reprehensible and theologically dangerous. In 

 this, the authority of Cuvier in regard to evolution acted as the au- 

 thority of Newton had done in regard to the undulatory theory of 

 light. 



In like manner the views of Oken met with resistance, especially 

 his deduction that the highest animals are the result of development, 

 not of creation. Man, he significantly says, has been developed, not 

 created. He conceived all Nature to be in a process of evolution. His 

 demonstration, that the bones of the skull are only vertebral modifi- 

 cations, however, reconciled many persons to a more favorable opinion 

 of his hypothesis of development. 



Geofiroy St.-Hilaire (1828) did not doubt that animals now living 

 are descended by an unbroken succession from extinct ones, by trans- 

 formation from form to form; that different species are degenerations 

 of the same type, being due to the influence of the environment 

 (monde ambiant). He thus became the opponent of Cuvier, and did 

 very much to break down the influence of that zoologist. In these 

 variations he considered that the organism is passive, differing in 

 this from Lamarck, who thought it active. His views of the influence 

 of the environment were very precise : thus he thought that birds 

 arose from reptiles, through the diminution of carbonic acid and in- 

 crease of oxygen in the air, at the time of the formation of coal ; the 

 activity of the animal circulation becoming greater, and the reptile 

 scales being transformed into the feathers of the bird. As is now 

 known, this was substantially a correct interpretation. 



Though the principles of the doctrine of evolution were thus thor- 

 oughly understood, the control of heredity, the influence of environ- 

 ment, the modeling by adaptation, public attention failed to be drawn 

 to it until 1844, when there was published in England an anonymous 

 book under the title of the " Vestiges of the Natural History of Cre- 

 ation." In this the author set forth Lamarck's views, and the work, 

 being clearly and attractively composed, passed through a great many 

 editions. Very fortunately, it may be said, it accepted some unsub- 

 stantiated facts and contained some physical mistakes. These tempted 

 many skillful and bitter criticisms of hostile theologians. The reviews 

 and journals were filled with their attacks and answers to them. 

 Thus, happily, the whole subject was brought into such prominence 

 that it could be withdrawn into obscurity no more. 



In the discussions of this book the author made use of a most im- 

 portant anatomical discovery, that even in the case of the highest 

 species, man himself, the embryo does not simply grow or increase in 

 size, but passes in succession through a series of forms, which, ex- 

 amined from epoch to epoch, are totally dissimilar. It had been the 

 vulgar opinion that after the first moment of conception all the parts 

 of the animal that is to be are present, and that they simply grow. 

 The human embryo, according to this, reaches birth very much in the 



