THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY, 



No. 65. DECEMBER 1842. 



XXXV. — On the Life and Writings of J. P. E. Vaucher. 

 By Alphonse DeCandolle. 



[Concluded from p. 168.] 



In general M. Vaucher distinguishes two species of fecun- 

 dation, one direct, the other indirect. In the first, the grains 

 of pollen are immediately applied or fall from the anther on 

 the stigma. This is the case with tulips, rushes, Petunia, 

 Myriophyllum, &c. 



In the second case, the grains of pollen at first fall on 

 other parts of the flower, and then act on the stigma in an in- 

 direct (detournee) manner, which he expresses vaguely by the 

 word emanation, or by analogous terms. In the indirect fe- 

 cundation, it often appears to him that the hairs of the inte- 

 rior of the corollas contribute, with the nectar, to determine 

 the action of the pollen. Here are some examples : — 



" The bottom of the flowers of the Lagenaria is a mellife- 

 rous basin, formed by the depression of the torus, and which 

 supplies the honeyed matter in such abundance, that it rises 

 between the stamens and bathes their summits Fecun- 

 dation takes place more easily in the Lagenaria than in the 

 other Cucurbit 'aceae, because the limb of. their corolla is hori- 

 zontally disposed ; nevertheless, as the anthers and the pistils 

 continue entirely merged (engages) in the tube, there can be 

 scarcely a doubt but that it takes place by means of the glu- 

 tinous and moist hairs which cover the interior part of the 

 petals, and to which the pollen at first attaches itself, whose 

 globules bursting transmit their emanations to the stigma. 

 After fecundation the corolla closes, and the honeyed humour 

 issues in abundance out of the cup, for the purpose of bathing 

 the stigma entirely and accomplishing the impregnation. This 

 manner of fecundation applies to the greater part of the Cu- 

 curbitacea." 



In speaking of the genus Clematis, M. Vaucher remarks a 

 lateral rather than an extrorse position in the anthers, as is 



Ann. fy Mag. N. Hist. Vol.x. R 



