124 Retrograde Varieties 



variety and need only compare these differ- 

 ences with those that distinguish the elementary 

 species of one and the same group from each 

 other. 



Two points are very striking. By far the 

 greatest part of the ordinary garden-varieties 

 differ from their species by a single sharp char- 

 acter only. In derivative cases two, three or 

 even more such characters may be combined in 

 one variety, for instance, a dwarfed variety of 

 the larkspur may at the same time bear white 

 flowers, or even double white flowers, but the 

 individuality of the single characters is not in 

 the least obscured by such combinations. 



The second point is the almost general oc- 

 currence of the same variety in extended series 

 of species. White and double flowers, varie- 

 gated leaves, dwarfs and many other instances 

 may be cited. It is precisely this universal 

 repetition of the same character that strikes us 

 as the essential feature of a variety. 



And again these two characteristics may now 

 be considered separately. Let us begin with 

 the sharpness of the varietal characters. In 

 this respect varieties differ most obviously 

 from elementary species. These are distin- 

 guished from their nearest allies in almost all 

 organs. There is no prominent distinctive 

 feature between the single forms of Draba 



