90 Selection Does Not Lead to Origin of Species. 



fleshy and they were as good vegetables as the ordinary 

 cultivated carrot. In the same way Carriere developed 

 in five years from the wild radish possessing small in- 

 edible roots a vegetable weighing from 3 to 6 hundred 

 grams. ^ Again Buckmann found that the roots of the 

 wild parsnip could be quickly increased in size by selec- 

 tion.^ 



We may conclude therefore that it does not take 

 more than a few years to reach that point which remains 

 constant in cultivation if selection is not slackened.^ 



At the beginning of this section we noted as the 

 second principle of selection, the belief that the result 

 of selection can persist independently of selection. 



Now, it is manifest that specific characters are abso- 

 lutely independent of selection. I am referring of course 

 to the mean characters of elementary species, for the 

 deviations from the mean are themselves the material for 

 selection. Over 200 species of Draba verna are known ; 

 these come true to seed and persist as such independently 

 of selection even when they are cultivated side by side 

 in the same garden. This is also true of very many 

 "species." Bateson has rendered good service in his 

 great book Materials for the Study of Variation by hav- 

 ing directed the searchlight of criticism on these weak 

 points in the theory of selection. He challenges this 

 theory to explain how the undeniable discontinuity in the 

 series of species can have arisen from the continuity of 

 ordinary variation. No such explanation has been of- 

 fered. For artificial selection does not lead to the origin 



* J. CosTANTiN, in Bull. Scientif. de Giard, 1897, p. 499. Com- 

 pare also LiNDLEY, TJicoyy of Horticulture, p. 313. 



" Darwin^ Das Variiren der Pflanzen und TJiierc, 1, p. 408. 



^ If the selection stops the plants revert to the wild form, and 

 this also in a short time. 



