30 



For the différent characters of Iberis amara -^ is respec- 



tively 0.114, 0.137, 0.13, 0.15; for Aneihmn graveolens 0.19 

 0.19 and 0.18 and for Malva vulgaris 0.071, 0.089 and 0.05. 

 It will be seen that for the same species thèse values 

 are nearly the same, while they differ considerably among 

 the three species. Doing the same with the badly-fed plants 

 we find a much greater différence between the variability- 

 coefficients of the varions characters of the same plant. 



For this culture ^ varies between 0.10 and 0.36 for the 

 M 



characters of Iberis amara and between 0.127 and 0.35 for 



those of Anethum graveolens. Hence it follows that the 



influence of nutrition on the variability of the différent 



properties of a plant is not the same; how much this 



influence varies will be seen from what follows. 



Comparing for each character scparately the variability 



of the well-fed with that of the badly-fed plants, we find 



that the différence between the variability-coef&cients for 



the two cultures varies greatly in différent cases ; for some 



characters it is very considérable, for others small. In order 



to compare thèse différences, they were divided by the 



value of ^ of the well-fed plants, as stated. The resulting 



number is the sensibility-coefficient of the variability. This 



sensibility-coeffiicient of ^ appears to vary between — 0.140 



and -h 0.29. In a comparison of varions characters of the 



same species the fact that the roots of the bad culture 



had more or less penetrated into the subsoil, obviously Is 



of no conséquence, so that the results obtained with Malva 



vulgaris are also available hère. 



Q 

 The sensibility-coefl&cient of ^ of Iberis amara is for the 



four characters respectively — 1.40, — 0.17, — 0.08 and 

 4- 0.09; for the characters of Anethum graveolens — 0.74, 



