SPH.EROPLEA. 83 



After fusion of the sexual nuclei the oospore develops its character- 

 istic wall (Fig. 29, G, H). Unfortunately Klebahn was unable to 

 trace the fate of the remaining nuclei. Whether they disappear indi- 

 vidually or, after fusion with each other, unite with the fusion nucleus, 

 is a matter of conjecture only. The investigations of Golenken (1900) 



FIG. 29. Fecundation of eggs and later development of spermatozoids. A-H, Spkaroplta braunii. 

 I-M, S. crassisepta. (After Klebahn.) 



A, egg with 3 nuclei, into which a sperm has just penetrated. 



B, same stage as A ; egg with 5 nuclei. 



C, egg with 4 nuclei and 5 pyrenoids ; the sperm nucleus has penetrated farther into egg 



D, sperm nucleus applied to functional nucleus of egg. 



E, fusion of two sexual nuclei. 

 F-H, maturation of oospore. 



I-K, later stages in development of spermatozoids. 



L, two spermatozoids. 



M, part of an oogonium showing fecundated eggs and spermatozoid* within. 



seem to throw further light upon the subject. As reported in the 

 Botanisches Centralblatt, 84, p. 284, 1900, this author, who observed 

 the sexual process in a variety of Sphceroplea annulina, which con- 

 tained multinucleate as well as uninucleate eggs, finds that in the 

 multinucleate eggs the nuclei lie near each other close to the surface, 

 and at a spot where the spermatozoids seem to enter. After fecunda- 

 tion the nuclei first distribute themselves regularly within the egg and 

 then finally fuse to form one nucleus. 



