1 92 CYSTOSPERME^. 



inflated cells occupied with sporangia or globules, is quite 

 consistent with the idea of these bodies being formed by the 

 contents of two cells, since each may be in contact on either 

 side with an inflated cell. In the very rare instances in which 

 three or four contlaaious cells occur, I have never noticed 

 a perfect globule in each of these, and even if such ever exist, 

 each globule yet might be formed not indeed of the entire 

 contents of two cells, but still of a portion of the green matter 

 of two. 



M. Leon le Clerk thus defines the genus Prolifera. 

 ^^ Fllamentls loculatls slmpllclbus, materia vlridi granulis 

 fulgidls aspersa totallter repletis. Singulo loculo, fructifica- 

 tlonis tempore, propriis virihus in glohiilam suam efformante, 

 Isto globulo intense vlridi ex loculo demisso novam plantam 

 eraittente." 



This definUlon of M. Leon le Clerk is exceedingly faulty. 

 It is not in each cell that the round globule is formed, but only 

 in occasional cells, or at most in alternate cells; and the asser- 

 tion that this globule really gives origin to a new plant, is 

 by no means established. Even M. J. Decalsne, who has 

 separated the ConjugatecB from the Algce zoospores, of Agardh, 

 does not state that he has witnessed their developement, but 

 infers this from the fact that the filaments of the Conjugatece, 

 whether young or old, in the same species, invariably present 

 the same diameter, and thus, as he supposed, could not pro- 

 ceed from organs so minute as the zoospores. 



M. Decalsne combats the idea of the disintegration of the 

 sporangia of the Conjugatece and VesiculifercB into zoospores, by 

 the fact that their contents are at all times fluid. This argu- 

 ment is, however, by no means conclusive, the contents of 

 the cells of the VesiculifercB, &c., are also generally fluid ; but 

 this fluid, when the proper period arrives, becomes fashioned 

 into distinct organs or zoospores, and the same may be the 

 case with the contents of the spores of the Zggnemata, as 

 asserted by Agardh. 



M. Decalsne also repudiates the idea of a double mode of 

 reproduction ; the spores he regards as the true and only re- 

 productive bodies of those Algce which possess them ; but it 



