THE STYLE AFTER FECUNDATION. 403 



uration of the stigma in the first place enables the 

 natural pollen to gain access ; but, if the absorption 

 of the pollen first applied causes immediate fecun- 

 dation, it cannot be explained how the subsequent 

 access of the natural dust should supersede it ; and 

 it has seemed to me that the natural pollen could 

 supersede that of an Azalea on the stigma of an 

 evergreen Rhododendron, even after the flower had 

 fallen off. 



" This point might be elucidated by cutting off 

 the stigma with portions of the style of various 

 lengths, at different periods after the application of 

 pollen, and seeing in what manner the operation 

 interferes with the fructification of the plant. 

 Gaertner thinks it doubtful whether the corolla is 

 essential to the fertilization of the stigma ; my 

 observation is, that its early destruction is very 

 prejudicial to the growth of the germen and stigma, 

 but that after their development it is not usually 

 essential. He observes that the corolla perishes 

 more quickly and completely after fecundation, and 

 is more persistent, and sometimes withers instead 

 of falling off in cases of hybrid impregnation ; but 

 he seems not to have distinguished the cases of 

 successful and abortive hybrid impregnation. I 

 observe that he admits that the viscous juice remains 

 on the stigma of Datura and Nicotiana two or three 

 days after fecundation, which does not exactly agree 

 with his theory, and seems to mark that the stigma 



