188 HOFMEISTER, ON 



The cells of the antheridia, which surround the central 

 cell, do not multiply any farther. The latter, however, 

 after a considerable increase of its circumference, is trans- 

 formed by a series of divisions into a globular group of 

 cubical cells (PL XXIV, figs. 10, 11). By the growth of 

 this cellular mass the cells of the covering layer are ex- 

 tended more and more into a tabular form, sometimes to 

 such an extent, that their cavities are entirely obliterated. 

 During the multiplication of the central cell their fluid 

 contents have become as clear as water. 



In each of the small tesselated cells within the antheri- 

 dium there is produced a flat spirally twisted spermatozoon 

 in the interior of a lenticular or globular vesicle, tlie latter 

 being apparently the primary nucleus of the small cell. 

 The turns of the spiral are but few in number. 



As the antheridium approaches maturity the walls of 

 the small internal cells are dissolved and the vesicles en- 

 closing the spermatozoa then lie free, enveloped in a granu- 

 lar mucilage, and surrounded by the compressed covering- 

 cells. If the antheridium is now exposed to moisture, 

 its contents swell, the flatly compressed cell of the apex 

 bursts in the middle in a stellate manner, and the vesicles 

 enclosing the spermatozoon escape through the fissures. 

 If the spermatozoa are fully- formed and ripe, the vesicles 

 when lying in water, exhibit a rotatory motion shortly after 

 their escape from the antheridium. I have often observed 

 that at the commencement of this motion, one of the ends 

 of the spermatozoon (usually the fore-end, which is the 

 thicker one and bears the cilia), protrudes from a fissure in 

 the vesicle. Suddenly the vesicle bursts by a wide open- 

 ing, the spermatozoon becomes free, and shoots out from it 

 in very rapid motion. 



The expanded fore-end of the spermatozoa, as has been 

 mentioned, is compressed laterally to a considerable ex- 

 tent ; the outer side of its spiral coils bears numerous deli- 

 cate cilia, which vibrate actively during its motion (PI. 

 XXIV, figs. 13, 15). At the opposite end the sperma- 

 tozoon gradually fines off into a very long hair-like termina- 



aiways foreign to the prothallium and are probably states of development of an 

 entophytal fungus. 



