By Thomas Bruges Flower, Esq. 



103 



of the floral organs, or from the increased size and weight of 

 the germen itself; because the former when in perfection did not 

 interfere with the nocturnal demersion, and the latter is scarcely 

 equal to the weight of the entire flower, which nevertheless had 

 hitherto continued to perform its periodic motions. And lastly, 

 because from the circumstance of the flower having been daily ele- 

 vated and supported several inches above the surface of the water, 

 the buoyancy of the floral organs could have contributed nothing 

 to the effect in question. The fertilization of the ovules being 

 effected, which can only take place in the air, the petals decay and 

 separate, and the germen is deposited at the bottom to ripen its 

 seeds, which are ultimately dispersed in the mud by the rupture 

 or dissolution of the germen itself. From the above considerations, 

 and others which may be brought to bear upon the subject, it may 

 be concluded that the motions of the flower stalk are determined 

 by the increased vital sensibility of the floral organs, consequent 

 upon the process of fertilization. 



Again the " NympJmacece" are very interesting, as affording a 

 good example of the mutual relationship and dependence of the 

 organs of plants. I shall briefly explain the doctrine, as it is at 

 present received : — 



1. The leaf is the simple type of all the floral organs, as far as 

 regards structure and relative disposition. 



2. Bracts are leaves modified in the first degree, differing but 

 little from the condition of the archetype. 



3. The calix consists of sepals, variously united, which are still 

 further modifications of the leaf. 



4. The corolla consists of petals, whose relationship to leaves is 

 still further obscured, by their having attained a greater delicacy 

 of texture, and a more brilliant and varied colouring. 



5. The stamen presents a filament and anther, the former being 

 analogous to the petiole of the leaf, and the latter to the lamina, 

 whose lateral edges are rolled inwards, and connected to the mid- 

 rib on the upper surface, forming two somewhat cylindrical cases, 

 for the generation and preservation of the pollen. 



6. The pistil consists of germen, style, and stigma. The germen 



