26 Latent and Semi-Latent Characters. 



ity of the phenomena which led Darwin to his theory of 

 the slow transformation of species. For at that time it 

 was believed that the inception of this process was to 

 be sought in the variation of a character already exist- 

 ing, whereas as a matter of fact the variation in question 

 is independent of the fluctuation of the existing char- 

 acters. 



6. The origin of a constant variety or a new species 

 could be easily imagined to occur in this way : First a 

 half race would arise from a pure race, then from this 

 half race a middle race and lastly, from this latter, a new 

 constant form. But this would be pure fancy, since it 

 is without any basis of fact. Besides in many cases the 

 intermediate stages are entirely wanting. 



§ 4. HALF RACES AND HALF CURVES. 



The study of anomalies must be based on the theory 

 that external factors can only be efficient in altering the 

 form of the plant if the power to react to them (or the 

 potentiality for the change) is already present.-^ ^'The 

 induction of malformations by external causes is no more 

 than the manifestation of latent potentialities," says Goe- 



BEL.- 



Every plant possesses a whole host of such latenV 

 potentialities. A single plant of Plantago lanceolata may 

 be raniosa, stipitata, and bracteata; it may have split 

 leaves and pitchers composed of one or two leaves; and 

 it may exhibit abnormal twisting and forked ears, or 

 present a whole series of other anomalies. The seeds of 

 a single self-fertilized plant will very often give rise to 



^ See Intraccllulave Pangenesis, p. 194. 

 ^GoEBEL^ Organo graphic, p. 158, 



