130 DARWINISM AND HUMAN LIFE 



the ante et post urhem conditam of biological history " ; 

 so it may be useful to inquire into the advances 

 that have been made in the study of heredity since 

 the beginning of Darwin's day.-^ 



Progress during the Darwinian Era. (1) 

 Demonstration of Heritable Qualities. — Before 1859 

 much attention was given to the demonstration 

 of the general fact of inheritance. In a large 

 treatise like that of Prosper Lucas (1847) many 

 hundreds of pages are devoted to proving, what we 

 now take for granted — that our start in hfe is no 

 haphazard afiair, but rigorously determined by our 

 parents and ancestors; that various pecuUarities, 

 important and trivial, useful and disadvantageous, 

 reappear as part of the inheritance generation 

 after generation. 



This demonstration of heritability is still going 

 on in reference to particular qualities ; thus we 

 have Prof. Karl Pearson's evidence in regard to 

 such subtle qualities as longevity and fecundity, 

 and his indirect proof that mental qualities illus- 

 trate the same law of inheritance as bodily qualities. 

 It is very desirable that more data should be accu- 

 mulated in regard to the heritability of variations, 

 whether Darwin's " individual variations," or De 

 Vries's " mutations." On the whole, however, it 

 may be said that, since Darwin's day, sufficient 

 evidence has been gathered to justify us in saying 

 that any hind of character which appears as an 

 inborn feature in an organism may be transmitted 

 to the next generation. 



(2) "Heredity" a Term for the Gendic Rela- 



^ See, for a detailed discussion of what is dealt with briefly in 

 this chapter, the author's treatise " Heredity " (Murray. London, 

 1908). 



