168 A. DeCandolle on the Life and Writings of Vaucher. 



this last part of the description. All that concerns the move- 

 ments of the stamens of the Agrimonia appears very accurate, 

 and, in the flowers which I have observed, pollen always fell 

 on the stigmas in consequence of these movements, but I have 

 not perceived any appearance of nectar. Perhaps M. Vaucher 

 had discovered a moment when this liquid is produced ; but 

 in any case I doubt whether it can act upon the pollen and 

 upon its transference. 



M. Vaucher considered the genus Lopezia as one of those 

 in which the action of the nectar in fecundation manifests it- 

 self with most elegance. He thus describes the phenomenon : 

 " There is at the bending part of their two petals, at the place 

 where the superior limb begins, a small spherical drop of 

 honeyed moisture, and opposite to it the stamen, as well as the 

 style, enveloped by a whitish and petiolated hood, which bota- 

 nists consider as an abortive stamen. At the moment when 

 the bilocular and extrorse anther opens its cells in order to 

 scatter its bluish and bright pollen, the hood throws itself 

 down on the inferior lip by a very marked flexure, and the 

 pollen abundantly covers the two melliferous drops which ab- 

 sorb it ; afterwards the withered anther is detached from the 

 filament, and the style, till then shapeless and as it were abor- 

 tive, lengthens insensibly and is terminated by a pretty glo- 

 bose, feathery and papillose stigma, which receives the con- 

 tents [emanations) of the pollen transmitted by the honeyed 

 moisture ; for it is impossible to suppose that the anther could 

 scatter its pollen immediately on a stigma not at the time in 

 existence, and whose style was situated at the side opposite to 

 the opening of the anthers ; fecundation is therefore, in this 

 case, evidently effected by means of the honeyed moisture, for 

 there is not in the cluster any neighbouring flower whose 

 anther could fecundate our stigma. Two little nectariferous 

 drops may also be remarked at the base of the corolla, similar 

 to those of the petals, and which equally conduce to the fecun- 

 dation." In admitting that the series of phenomena takes 

 place in Lopezia just as the author describes, we cannot help 

 asking how the pollen, after falling into the honeyed moisture 

 of the petals, sends emanations at a later period to the stigma. 

 What are these emanations} What transportation can take 

 place of the drop containing the pollen to the stigma ? Here, 

 it must be confessed, is a gap in the observation or in the de- 

 scription. Perhaps the sense of the passage will be explained 

 by an attentive examination of nature, for our author was most 

 honest, and did not write in order to propose enigmas for bo- 

 tanists. 



[To be continued.] 



