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be found in which this process is independent of the 

 hygroscopic condition of the air, was found to be correct. 

 If the flowers are placed under a glass bell-jar, the air 

 in which is saturated with water-vapour, the anthers, of 

 many plants burst at about the same time as those of 

 flowers which are put outside the moist space in the 

 open air. 



This led me to arranging some experiments, yielding 

 the following results : 



1. If in a flower of Diervilla (Wehjelia) rosea or flori- 

 hunda, which is in progress of unfolding itself, one ofthe 

 stamens is squeezed by means of a pair of pincers, so that 

 the drainage of water from the stamen downwards is dis- 

 turbed, the four anthers whose stamens hâve remained 

 intact, spring open, but the fifth remains closed. With 

 this plant it is not necessary to place the flower in a 

 moist space; the same resuit is generally obtained if the 

 flower remains attached to the plant. 



If a flower is placed in the moist space together with 

 the loose anthers of another flower, those which are atta- 

 ched to the flower spring open; the loose ones don't. If 

 only the corolla with the stamens attached to it is placed 

 in the moist space, ihe anthers open as well as those of 

 the complète flower. Consequently the nectary which is 

 found in the middle of the flower at the side of the ovary, 

 exerts no direct influence on the bursting of the anthers. 

 If further a stamen is prepared in its full length and 

 placed in the moist space together with some loose anthers, 

 the anthers of the stamen burst, whereas the loose anthers 

 remain closed. 



From thèse experiments we infer that the anthers open 

 under the influence ofthe stamen whether or not connected 

 with the corolla. Now an investigation with Fehling's 

 solution shows that as well the stamen as the whole 



