FECUNDATION IN THE VEGETABLE KINGDOM. 91 



RADLKOFER'S PROCESS OF FECUNDATION IN THE 

 VEGETABLE KINGDOM.^ 



This gives in English, and in an accessible form, a sys- 

 tematic and historical survey of the whole subject of vegetable 

 fecundation, including the recent discoveries of Pringsheim, 

 Cohn, Braun, and Bary. 



As to Fungi and Lichens^ — thanks to the observations of 

 Itzigsohn upon the latter, and the most useful and persevering 

 investigations of Tulasne upon both families, — the analogues 

 of male organs in all probability are discovered, and their 

 general presence recognized ; but the fact of fecundation is 

 not made out. 



In the lower or green Algce^ fecundation was first demon- 

 strated by Pringsheim. The " horns " of Vaucheria which 

 Vaucher half a century ago observed and conjectured to be 

 male organs, Pringsheim proved to be so, having seen them 

 open at the summit and emit a great number of free-moving 

 corpuscles (spermatozoids), many of which found their way 

 into the now open orifice of the protuberance, which contains 

 the forming spore, and were seen crowding against it, after 

 which a membrane of cellulose appears over the surface of 

 the mass of protoplasm and completes the spore. Whether 

 one or more of the spermatozoids actually penetrates the 

 protoplasm and so is included within the cell-membrane is 

 uncertain ; but Pringsheim thought it was the case, from 

 having detected a colorless corpuscle like one of the sperma- 

 tozoids inside of the membrane. Next Pringsheim demon- 

 strated a similar fecundation in Qlldogonium. His results, 

 briefly published in the proceedings of the Berlin Academy, 

 and thence translated into French and English, are now 

 given in detail in the first part of his " Jahrbiicher," noticed 

 above. OEdogonium consists of a row of cylindrical cells. 



^ Der Befruchtungsprocess im Pflanzenreiche. L. Radlkofer. Leipsic, 

 1857. (English translation by Arthur Henfrey in Annales and Magazine 

 of Natural History, October and November, 1857.) (American Journal 

 of Science and Arts, 2 ser., xxv. 112.) 



