Biographical Memoir of Baron de Beauvois. 5 



In the midst of that green powder which fills the urns of the 

 mosses, and which Hedwig considers as the seed, is a kind of 

 nucleus or small axis, more or less inflated, named by botanists 

 the columella. 



Those who had observed its interior had only seen in it a more 

 or less cellular parenchyma. M. de Beauvois thought he re- 

 marked in it very small grains, and immediately [conceived these 

 to be the true seeds. The green powder which fills these urns 

 was, in his eyes, nothing else than the pollen. The motions of 

 the ciliae, with which the edges of the urn are furnished, were 

 intended to compress this pollen against the seeds, in order to 

 fecundate them at the moment when they are making their 

 escape. And when it was objected to this view, that Hedwig 

 had raised mosses by sowing the green powder, he replied, that 

 undoubtedly Hedwig had sown, at the same time, without per- 

 ceiving it, the other finer powder contained in the columella. 



It will be obvious, that, to confirm an opinion so new, it 

 would have been necessary not only to shew that this powder of 

 the columella actually exists, but also to be able to sow it sepa- 

 rately from the green powder. However, it does not appear 

 that M. de Beauvois ever tried this latter experiment. 



The same objection might be made to his opinion respecting 

 the lycopodia. In these cryptogamic plants there are observed 

 capsules very diiFerent from those of the mosses, and which con- 

 tain an inflammable powder, well known from its being used in 

 public exhibitions. This powder, which Hedwig also took for 

 the seed, appeared incontestibly to M. de Beauvois to be the 

 pollen ; but among this powder are mingled some transparent 

 bodies, which he considered as a kind of buds or bulbs, capable 

 of producing new plants. These, in his opinion, were the bo- 

 dies that had germinated in Hed wig's experiments. The true 

 seeds are larger grains contained in small capsules, placed in the 

 axillae of the leaves of the lower part of the stem ; but we do not 

 know that he ever attempted to make them germinate, although 

 the experiment was much easier than with those of mosses. 



The Academy, whose principle it has always been to attend 

 only to positive calculations or experiments, could not therefore 

 consider the opinion which M. de Beauvois had submitted to it 

 as demonstrated : and although M. de Jussieu, in his Genera i 



