11 



" When this happens within heteroblastic species or genera, 

 then there follows a corresponding difference in the entire mor- 

 phological expression of the individual forms. We rank these 

 forms as individual variations if observation or experiment 

 demonstrates their connection with the 'normal.'" {Limosdla 

 presents an example of this.) " We call them species if such 

 experience is wanting. But often these standards are uncertain." 

 One recalls very distinctly an example in the case of Cavipannla 

 rotundifolia. Of their early-blooming form, Goebel rightly says, 

 they would, " in another botanical district and occurring in larger 

 number, be considered without hesitation as a different species 

 from Campanula rotundifolia. There is not the slightest doubt 

 but that in fact many so-called ' species ' bear the same relation 

 to other species as the Schleissheim Campanida (p. 86) does to 

 the ' normal ' plants, that they also stand mutually in the relation 

 of helikomorphic forms." 



" Often phase-forms prove themselves to be ' epharmons ' 

 {Epharmoscii). Theoretically they must quite frequently begin 

 as such, because the relation between v^egetative growth and 

 reproduction is so labile, and because external conditions are in 

 continual change?" 



" In each case these epharmonic phase-forms will endure as 

 long as the determinative conditions remain nearly similar. They 

 may, indeed, exist under circumstances of very long duration. 

 And thereby they acquire the possibility of becoming fixed 

 through heredity and of losing more and more the primary strict 

 dependence upon external circumstances." 



" This case has found realization in many similar forms. * * * 

 The Australian acacias form their phyllodes even in our houses. 

 I have seen examples of Eucalyptus Risdoni that escape from 

 culture of European gardens and bear inflorescences as in their 

 home locality." 



" Heredity has also been demonstrated in the case of the 

 ' seasonal dimorphic ' species. Von Wettstein has cultivated 

 Euphrasia Rostkoviatia and E. montana through three years in 

 the botanical garden at Prague under entirely similar external 

 conditions. The two plants proved themselves fully constant in 



