Progression, Retrogression and Degression. 69 



f asciations. ^ As a constant horticultural variety it occurs 

 in Celosia cristafa; but as a specific character, so far as 

 I know, it does not occur. This is, however, true of the 

 almost equally widely distributed split leaves (as in Boeli- 

 meria biloba), of adherences (Solanuin), of flowers on 

 leaves (Helzvingia ntsci flora and others) and of numer- 

 ous other anomalies of which Casimir de Candolle has 

 given a valuable general account.^ He calls them "Varia- 

 tions taxinomiqiies'' ; whereas anomalies which do not 

 occur as specific characters such as fasciation, twisting, 

 virescence and sterile varieties, are designated by him as 

 ataxinomous. I take the following further instances 

 from his list : Connation of opposites leaves, which oc- 

 curs normally in Dipsacus, Lonicera and others, or of the 

 cotyledons (amphisyncotyly, normal in Sieyos) ; Pitch- 

 ers, normal in Sarracenia etc., and in the peltate leaves, 

 as for instance Eucalyptus citriodora ; foliacious excres- 

 cences on the leaves, normal in Senecio sagittifolius from 

 Uruguay, and on petals, normal in Petaquia saniculae- 

 folia and as a sport in Clarkia elegans; Synanthy in 

 Lonicera, and so on. 



For our purposes, however, the question is not which 

 anomalies can also occur as specific characters, but con- 

 versely which specific characters can also occur as anom- 

 alies in other species. For our task is to deal with the 

 problem of species and especially to provide an answer 

 to the question how far their characters can be derived 

 from more or less widely distributed latent qualities 

 which have existed for a long time in the vegetable king- 

 dom or in particular groups of it. With this end in view 



2 



5-6. 



^ See Vol. I, Figs. 34 and 35 on pp. 182-183. 

 C. DE Candolle, Rcmarqucs sur la tcraiologie vcgctalc, 1896, pp. 



