110 VEGETABLE ORGANOGRAPHY. 



petaloid and rumpled : this seems to confirm the opinion 

 of Desvaux, who considered the outer row as the calyx, 

 and the inner the corolla. But, besides the reasons 

 above mentioned against this opinion, it must be added, 

 that the rumpled aestivation results only from an extra- 

 ordinary development of the organs. Thus, the petals 

 of the Poppy (PL 19, fig. 1), which are rumpled in 

 aestivation when examined collectively, appear evidently 

 alternate when examined separately, especially in double 

 flowers where their number diminishes the rumpling. 



The relative position of the stamens with regard to 

 each other has less apparent influence upon the structure 

 of the flower, seeing that the form of these organs 

 always causes them to have sufficient space to develop 

 in without overlapping ; they only present, in this 

 respect, differences in the number of concentric rows, 

 the proportion of their size, the number of each row, 

 and the degree of their cohesion, of which I have else- 

 where spoken. I have already treated sufficiently upon 

 the position of the carpels. 



The direction of the organs forms also part of the 

 history of their prefloration. Most of them spring 

 erect, as in all the examples of aestivation which I have 

 mentioned ; but there are some folded or rolled 

 inwards in a remarkable manner; thus, the calyces of 

 the Valerians and Centhranthus have the limb rolled 

 inwards upon itself, so as only to present, at the period 

 of flowering, a kind of ring which is developed at the 

 fall of the corolla: this is Involute ^Estivation. 

 The stamens of the Melastomaceae have their filaments 

 folded upon themselves, so that the anthers are pendent 

 in the interior of the bud ; this is an example of Re- 

 plicate ^Estivation. The carpels of Spircea ulmaria, 

 and still more those of Helicteres, are twisted spirally 

 upon one another, in the manner of twisted aestivations; 





