An Introduction to a Biology 



heavier task of forcing mankind to believe in it. To satisfy 

 oneself of the truth of evolution is the work of a philosopher ; 

 to con\TLnce other people of this truth is a labour of Hercules. 



Erasmus Darwin married twice. By his first wife he was 

 grandfather to Charles Darwin, by his second to Francis 

 Galton. " His hereditary influence," says Galton (" Memories 

 of My Life," p. 7), " seems to have been very strong. His 

 son Charles, who died at the early age of twenty of a dis- 

 section wound, was a medical student of extraordinary pro- 

 mise." Erasmus may not have been — probably was not — 

 the first to perceive the fact of evolution ; there can be little 

 doubt that Bufion was before him. But with Erasmus 

 Darwin the business of making evolution credible passed 

 over once and for all to the " nation of shopkeepers " and 

 the Darwin family. Not only was Erasmus Darwin's enun- 

 ciation of the doctrine of evolution less equivocal than 

 Buffon's (through no fault of the latter, however), but the 

 sudden conversion of Lamarck, late in hfe, to a behef in 

 evolution followed so closely after the appearance of a French 

 translation of "The Loves of the Plants" by E. Darwin, 

 as to leave little room for doubt that the two events were 

 causally connected. Of Charles Darwin's participation in 

 the task of making evolution credible no more need be said. 



We must now turn to the part played by his cousin. 

 Galton, by laying the foundation of an exact science of 

 heredity, not only took steps to fill in the most serious gap 

 in the evolutionary hypothesis, but sowed the seed of a 

 tree which \\ill furnish the best, if not the only, antidote 

 to that outbreak of a priori speculation which followed the 

 publication of the " Origin." Galton' s vivid perception of 

 the necessity of having things surely and certainly described 

 before any attempt was made to explain them, found its 

 expression in the application of statistical methods to the 

 study of biological problems. It was not only by that part 

 of his work which laid the foundations of Biometry that 

 Galton supplemented the work of Darwin ; he also drove 



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