60 Institute of France. 



According to some observers, however, it does not burst in water 

 like pollen ; and it is admitted by ail, that when it is spread on 

 the ground it grows, and produces lyco])odia. But the former pro- 

 petty is not of an essential nature ; and M. de Beauvois ascribes 

 the latter to small j^lobules, which he has distinguished among 

 this du-.t, and which he regards, as small bulbs or eyes ; so that, 

 according to him, it is not the yellow dust which springs up, but 

 these })ulbs, which cannot be separated from thein. As to the 

 true seeds which the pollen would be destined to fecundate, 

 ?vl. de Beauvois finds them in other capsules, placed sometimes 

 between and sometimes imder the former, aiid containing only 

 small round seeds, transparent and larger than those of the yellow 

 pcvt'der. But these peculiar capsules have only been found in 

 about one third of the various species of lycopodia, and they 

 have been looked for in vain in the rest. 



M. Desvaux agrees almost entirely with M. de Beauvois as 

 to the facts, but denies the conseOjUences : lie sees nothing in the 

 vellow dust but bulbs or eyes, or, as he calls them, propngnlts, 

 which have no occasion for fecundation i:i order to germinate. 

 The other seeds observed by M. de Beauvois are merely, he 

 sap, if we may judge from their small number, their transpa- 

 rency, and irregular figure, abortive propagz/les. 



M. de Beauvois answers, by showing that all the definitions 

 which the most learned botanists have given of the seed are ap- 

 plicable to these globules ; and setting out from the principle 

 diat the existence of a seed presupposes that of the female sex, 

 and that the existence of one sex implies that of another, he ad- 

 heres to his first ideas. 



His antagonist replies, that a nominal definition formed ac- 

 cording to the received ideas cannot decide a process wherein 

 these same ideas are disputed, atid that the visible characters of 

 structure, recognised in all the seeds, are far from being verified 

 here, on account of the smallnessof the object. 



We find that the discussion now becomes metaphysical. The 

 only method of ascertaining the point in the eyes of hesitating 

 physiologists, would be to operate the fecundation of what we 

 regard as pistils by means of what we regard as pollen ; but who 

 could flatter himself with making on organs so delicate, the ex- 

 periment which has so plainly demonstrated the existence of 

 the sexes in common plants ? 



M. DesvMux has given besides a methodical distribution of all 

 the known Ivcopodia, adding some subdivisions to those esta- 

 blisl.ed by M. de Beauvois in a preceding work on the same sub- 

 ject, and taking for his principal ba?es the existence of the two 

 sorts of capsules, and the division of the capsules into com- 

 partments more or less numerous. 



M. Decan- 



