( 14) 



the green leaves and tlie bracts round them, j)kints that had been 

 cnt open had to be used for the measurements, in which the flower 

 was laid bare over its full length. For this purpose flowers were 

 chosen which were still surrounded by bracts and entirely closed 

 and the top of which became just visible above the ground. It 

 appeared, however, that at this stage the stem on which the flower 

 is situated, had reached about its full length and only grew a few 

 millimetres more. The further longitudinal growth which is very 

 considerable and brings the flower above the ground is nearly wholly 

 caused by the corolline tube between the ovary and the loose slips 

 of the perianth. Only to this stage I paid attention. Some measure- 

 ments of the corolline tube may follow : 



a. flower undamaged. 



b. corolline lobes removed. 



6'. corolline lobes, stamens and pistil cut away at the upper 

 end of the coalescent corolline tube. 



So removal of the terminal organs has not remained without 

 influence on the growth of the corolline tube, but has not been able 

 to check it to the same extent as in the preceding cases. 



It deserves notice that removing the anthers and stigmas did not 

 prevent the stamens and styles to reach about their normal length. 



Suininarij. The iuN^estigation has shown that the normal longi- 

 tudinal growth of the stem with Eranthw Idenialis is only possible 

 when the whorl of leaves at the top is present, while the flower 

 exercises no influence on it. This latter is also the case with 

 the stem of Galanthu.^ nivalis and JVarcissifs Pseudo- Narcissus ; 

 the flower-stalk however, in these two plants, is checked in growth 

 as soon as the flower is cut, the ovary proving to be of especial 

 importance. With Tidipa Ges7ieriana it is chiefly the perianth that 

 rules the longitudinal growth of the upper internode ; with Crocus 

 vernus, Anally, the growth of corolline tube, stamens and style is 

 in a high degree independent of the presence of petal lobes as well 

 as of anthers and stigmas. 



