120 



BOTANY 



the body of the antheridium is composed of eight cells. Each of these octants 

 divides by a periclinal wall with an outer and inner cell (Fig. 91, C), and the 

 latter of these by a second periclinal wall into two more. Thus each octant 

 is divided into three concentrically arranged cells (D). The cell between the 

 body of the antheridium and the basal node pushes up between the cells of the 

 antheridium and becomes later very conspicuous (Fig. 91, E). 



As the antheridium increases in size, the eight outer cells become much ex- 

 panded laterally and form as many triangular plates, with deeply infolded cell- 



B 



FIG. 91. A, manubrium, m, of Chara sp., bearing numerous spermatic filaments 

 attached to the capitula, c (X 75). B, longitudinal section of a young leaf of 

 C. fragilis, showing the position of the sexual organs ; these arise from the basal 

 node of a leaflet, which is joined to a node of the leaf by the basal internode, y 

 (X 200). C, D, E, development of the antheridium, seen in longitudinal section 

 (X 200) . F, secondary capitulum, c, with four young spermatic filaments. G, end 

 of a ripe spermatic filament, showing the spermatozoids within the cells (x 500). 

 H, two free spermatozoids ( X 500) . 



walls, constituting the so-called "Shields," of which the antheridial wall is 

 made up. The chromatophores within these cells, as well as those in the second 

 series of cells, the Manubria, become of an orange-scarlet color as the antherid- 

 ium ripens, and make it very conspicuous. 



The manubrium (Fig. 91, A, m), or second cell of each octant, remains undi- 

 vided, increases much in length but very little in breadth, and forms a club- 

 shaped cell attached to the middle of each shield and projecting into the cavity 

 of the antheridium. 



