426 BIOLOGY AND ITS MAKERS 



tinued, 'and you can not form any idea of what I felt on 

 receiving the news of the meeting on the 19th. In Geoffroy 

 de Saint-Hilaire we have now a mighty ally for a long time 

 to come. But I see also how great the sympathy of the 

 French scientific world must be in this affair, for, in spite of 

 the terrible political excitement, the meeting on the 19th 

 was attended by a full house. The best of it is, however, 

 that the synthetic treatment of nature, introduced into 

 France by Geoffroy, can now no longer be stopped. This 

 matter has now become public through the discussions in the 

 Academy, carried on in the presence of a large audience; 

 it can no longer be referred to secret committees, or be settled 

 or suppressed behind closed doors.' " 



Influence of Lyell's Principles of Geology. — But just as 

 Cuvier was triumphing over Saint-Hilaire a work was being 

 published in England which was destined to overthrow the 

 position of Cuvier and to bring again a sufficient foundation 

 for the basis of mutability of species. I refer to Lyell's 

 Principles of Geology, the influence of which has already 

 been spoken of in Chapter XV. Lyell laid down the prin- 

 ciple that we are to interpret occurrences in the past in the 

 terms of what is occurring in the present. He demonstrated 

 that observations upon the present show that the surface of 

 the earth is undergoing gradually slow changes through the 

 action of various agents, and he pointed out that we must 

 view the occurrences in the past in the light of occurrences 

 in the present. Once this was applied to animal forms it 

 became evident that the observations upon animals and plants 

 in the present must be applied to the life of the fossil series. 



These ideas, then, paved the way for the conception of 

 changes in nature as being one continuous series. 



H. Spencer. — In 1852 came the publication of Herbert 

 Spencer in the Leader, in which he came very near antici- 

 pating the doctrine of natural selection. He advanced the 



