Evolution of Evolution-Theory. 223 



able to suggest an answer to two difficult questions 

 How are intermediate links so often absent? and how 

 are new types kept from the blending effects of inter- 

 breeding 1 ? 



Robert Chambers (1802-1871), the anonymous author 

 of Vestiges of the Natural History of Creation (1844, 

 loth ed. 1853), expounded the evidences of evolution 

 forcibly, though not always accurately, and sought 

 in the environment not only the immediate prompting 

 cause of modification, but the agency which directs 

 and limits the progressive impulse with which he sup- 

 posed all life to be endowed. He was well acquainted 

 with contemporary writers, and expresses a combination 

 of Buffon's and Geoffrey St. Hilaire's emphasis on en- 

 vironmental modification with Aristotle's doctrine of 

 a perfecting principle. 



As Darwin's brother remarked, the idea of natural 

 selection is logically so simple that " someone must 

 have thought of it before ". And we have seen that it 

 was at least hinted at by various writers from the time 

 of Empedocles. It is necessary, however, to distinguish 

 between the mere recognition of elimination and the 

 working out of the idea of selection as the mechanism 

 of progressive adaptation. The whole credit of de- 

 veloping the idea of selection into a complete working 

 hypothesis belongs to Darwin and Wallace, though 

 they were undoubtedly and avowedly anticipated as 

 regards the suggestion of the idea. 



Thus Darwin notices the paper read by Dr. W. C. 

 Wells in 1813 and published in 1818, in which the idea 

 of natural selection is clearly applied to races of man- 

 kind and to the origin of single characters. Darwin 

 also recognizes that Patrick Matthew, who hid his 

 treasure in an appendix to a work entitled Naval Timber 

 and Arboriculture (1831), "clearly saw the force of the 

 principle of natural selection ". The idea is also said 

 to have been anticipated by Etienne Geoffroy St. Hilaire, 

 and by the veteran French botanist Charles Naudin 



(1852). 



Darwin did three chief services to evolution-doctrine. 

 (a) By his patient, scholarly, and pre-eminently fair- 



