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, Spharoplea 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 spermatozoids 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 Spkceroplea 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. 



