( 10) 



of it were cut awav. On the otlier liaiid the growth was very con- 

 siderably impeded by removijig tlie whorl of green leaves. This will 

 be seen from the following measurements. 



Eranthis-siem, on which only the three lea^TS under the flower 

 have been preserved, the flower itself having been removed : 



Another example of the same case: 



Date 6.2 10.2 13.2 17.2 22.2 26.2 

 Length in mm. 58 104 129 135 135 :I35 



Eranthis-siem of which the basal whorl has been cut away, the 

 flower remaining intact: 



Date 6.2 10.2 13.2 17.2 19.2 

 Length in mm. 86 96 97 100 100 



Another example of the same case : 



Date 7.2 11.2 15.2 17.2 



Length in mm. 59 72 74 74 



Hence a stem which had been bereft of its flower grew in length 

 in a period of twelve days 176 "/„ in the first and 133 "/„ in the 

 second experiment, this increase in length being only 16 "/„ and 25 "/„ 

 respectively in the same time with a stem on which the flower had 

 been preserved but the whorl of leaves removed. 



The influence which the presence of the leaf-whorl has on growth 

 follows clearly enough from this. Also in the other cases Avhich I 

 investigated, the growth of stems that bore flowers only, may have 

 been a little greater than of stems from which the leaf-whorl as 

 well as the flower had been removed, it is certain, however, that 

 the longitudinal growth is chiefly regulated by the presence of the 

 green leaves. 



A related fact is that after removal of the leaf-whorl the flo^ver 

 raises itself only very slowly and often only partly. 



Although the supposition is not very probable, it might be presumed 

 that the observed effect of the three leaA^es is caused by the circum- 

 stance that they ha\'e to provide the stem with food. That this 



