The Origin of Liiiaria Vulyaris Pcloria. 217 



(jaris liciiii pel aria, and always suddenly. The very gen- 

 eral occurrence of this race and the fact that intermediate 

 forms between it and the fully developed Pcloria have 

 never been mentioned by botanists, give support to this 

 h}pothesis 



If this view is correct we have here a mutation which 

 is not limited to a period but continues to appear from 

 time to time during the course of the ages. Its appear- 

 ance in every single case is independent of the others, at 

 least so far as external conditions are concerned. In 

 this sense it is polyphyletic. 



A point which favors this view is the fact that it is 

 not a member of a definite group of mutations as are the 

 subspecies of Draba vcrna, Viola tricolor and others. 

 Linaria vulgaris, it is true, frequently gives rise to other 

 kinds of variations such as the Pcloria ancctaria and the 

 Catacorolla, both of which have occasionally appeared 

 in my own cultures, but nothing is on record concerning 

 the relation between these and the Pcloria nectaria which 

 I have studied. 



If we compare these results with those which we have 

 described above for Antirrhinum inajus striatum (§ 14, 

 p. 134), we see that Linaria vulg. hemipcloria is obviously 

 a half race; and that L. vulg. pcloria, whose partial con- 

 stancy seems analogous to that of the striped snapdragon, 

 may perhaps be regarded as parallel to this. These two 

 races fluctuate so as to approach one another, so to speak, 

 occasionally overstepping the common boundary either in 

 single flowers (L. vulg. hemipcloria) or in whole plants 



(L. vulg. pcloria). 



* * * 



We now come to the most important ]:)oint to which 

 our results and conclusions lead us — namely the com- 



