28o 



PLANT LIFE. 



but the seed plants was described in Part I. The forms of 

 the sperroaries are as follows : 



383. Chara. — The compound spermary of Chara (fig. 

 313) consists of a spherical case composed of four triangular, 

 plate-like cells ; from the inner face of each projects a 

 handle-like cell to whose end are attached 24 filaments, each 

 composed of 100—200 disk-shaped cells. Each of these con- 



Fig. 312. — Development of a sperm of a liverwort (Pellia epifihylla) 



etc 



, mother cell 

 with nucleus, the" latter approaching the wall ; b to k, nucleus elongating and curving 

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

 peripheral protoplasm ; /', also an edge view; k, mature sperm, free. Magnified iooo 

 diam. — After Guignard. 



tains a sperm; so that each spermary produces 20,000- 

 40,000 sperms. 



384. Mossworts and fernworts. — In the mossworts the 

 spermary is a stalked body, whose internal cells are the sperm 

 mother cells, the outer layer forming the spermary wall (fig. 



In the fernworts the spermary is sessile and the number of 

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

 reduction in size of the gametophyte (see ^[ 395). When 

 the gametophyte is greatly reduced, as in the club -mosses, 

 a single spermary only is formed, which is even larger 

 than the rest of the gametophyte (fig. 315). 



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

 phyte begins to be formed before the microspore leaves the 

 sporangium. In gymnosperms the spore divides into two to 

 six cells, one or two of which represent the vegetative part 



