EXPLANATION OF THE FIGURES. 



The figures are ail reproduced at about half size. In 

 the original figures the distances of the intervais, placed 

 along the absciss, are 1 cm., each mm. of the ordinates 

 having a value of 1%. So we can find from the length 

 of the ordinates the percentage number for each interval. 

 In most figures the ordinates are drawn between the two 

 numbers indicating the interval, only in figs. X, XIII and 

 XIV, where the observations are not arranged in groups, 

 the ordinates stand above the number. The curves ofthe 

 well-fed plants are drawn in continuous lines, those of 

 the badly-fed plants are dotted. 



Fig. I. Iberis amara. Length of the plant from the 

 base of the principal stem to the top of the 

 inflorescence of this latter, in cm. 



„ II. Iberis amara. Length of the leaf, in cm. 



„ III. Iberis amara. Number of silicles of the inflore- 

 scence of the principal stem. 



„ IV. Iberis amara. Number of branches of the second 

 order. 



„ V. Iberis amara. Number of branches of the third 

 order. 



„ VI. Anethum graveolens. Number of umbel-rays. 



„ VIL Anethmn graveolens. Number of flowers in the 

 umbellet. 



„ VIII. Anethum graveolens. Number 'of lobes of the 

 first leaf. 



„ IX. Scandix Pecten-Veneris. Number of lobes of the 

 first leaf. 



