28o 



PLAXr LIFE. 



l)Ut the seed piaiits was desrribed in Part I. 'I'he forms of 

 the spermaries are as iolhiws : 



383. Chara. — 'I'he compound siiermary of Chara (fig. 

 313) consists of a splierical case comijosed of fmr triangular, 

 plate-Uke cells ; from the inner face of eacli projects a 

 handledike cell to whose end are attached 24 filaments, each 

 composed of 100-200 disk-shaped cells. I'^ach of these con- 



Fig. 312. — Development of a sperm of a liverwort { PcIUa e/>i/'hyila\. n, mother cell 

 with nucleus, the latter ajDproaching the wall ; /■ to //, nucleus elongating and curving 

 into an arc, and finally a spiral coil ; r, an edge view, showing origin of cilia from 

 periplieral iirotoplasm ; /, also an edge view ; /-, mature s[)erm, free. Magnified looo 

 diam. — After Guignard. 



tains a sperm ; so that each sperniar}' i)Tothices 20,000- 

 40,000 sperms. 



384. Mossworts and fernworts. — In the mossworts the 

 spermar\- is a stalked body, \A'liose internal cells are the si)erm 

 motlier cells, the outer layer fornung the spermar)^ wall (fig. 



311)- 



In the fernworts the s])ermary is sessile and tlie number of 



mother cells is much smaller (fig. 314), corresponding lo the 



reduction in size of the gametoph\te (see • 395). \\'hcn 



the gauietoph\'te is greatly reduced, as iu the thih-uiosscs, 



a single spcrmarv only is formed, winch is e\cn larger 



than the I'cst of the gametophvte (fig. 315). 



385. Seed plants. — In the seed plants the male ganieto- 

 phyte begins to be formed before tlie nu"crosporc lea\es the 

 sporangiimi. In gymuospcrms the spcu'c di\ides into two to 

 si.x cells, one or two of \\'liich reiiresent the \i'gctati\'e part 



