84 Selection Does Not Lead to Origin of Species. 



a series in 1893 varying between 12 and 22 and with 

 a mean of 19 rays. I now chose the seed from 13-rayed 

 plants and got in 1894 a generation varying between 13 

 and 22 and with a mean of 18. The regression amounted 

 in this experiment to about % ; that is to say the children 

 deviated only one-third as much from the type of their 

 species as their parents did.^ 



12 13 n J.i 16 77 IS 19 20 V 2i :'J 2* 2S 



Fig. 19. Madia elegans. Successive generations 

 showing the result of the selection of examples 

 with the smallest number of ray-florets. The fig- 



' ures at the base of the ordinates give the number 

 of these florets. The limit of the variation fan for 

 1904 coincides on the left side with the 13 rays 

 ordinate. 



On the other hand a character perpetuates itself un- 

 altered or almost so if the plant bearing it is propagated 

 vegetatively. The descendants are of course nothing 

 more than parts of the original plant ; the products of a 

 single seed. Hundreds or even thousands of them can 

 be put on the market, but together they constitute merely 

 parts of a single individual. 



The whole so-called variety, thus, consists in this 



See also the pedigree of my experiment with maize on p. y^. 



