THE LAWS OF HEREDITY 



much more commonly than had hitherto been 

 supposed, and that such hybridization is often 

 responsible for the production of new forms that 

 may play an important part in the scheme of evo- 

 lution. He believes, indeed, that hybridization 

 largely accounts for the origin of those variations 

 which Darwin had been content to speak of as 

 "spontaneous," and which are recognized as the 

 material with which natural selection works in 

 developing new species. 



MENDELIAN HEREDITY 



The striking results in the production of new 

 varieties through hybridization that Mr. Burbank 

 had attained became known to horticulturists 

 and biologists, and probably had an important 

 share in preparing the world to look with interest 

 on the experiments of the Austro-Silesian monk, 

 Mendel, when the obscure report that this ex- 

 perimenter had published as long ago as 1863 

 was rediscovered just at the close of the nine- 

 teenth century. 



Mendel, working chiefly with the garden pea, 

 had paid attention (as we have already seen) to 

 a few conspicuous characters regarding which 

 different races of garden peas differ. 



He had observed the mutual relations in the 

 inheritance of such qualities as tallness versus 

 shortness of vine, pinkness versus whiteness of 

 flower, yellowness versus greenness of pod, etc., 

 and had traced very definitely and with scientific 



[281] 



