Brixton and Taylor: Life History of Schizaea pusilla 9 



One or two were found to start out from the center of a cell of a 

 filament. The antheridia are produced in great quantities but a 

 great number of them are aborted, and the majority of antheridia 

 terminate a branch of two cells. They occur nearer the apex of the 

 filaments than the archegonia, and sometimes on the same filament 

 with the archegonia (Fig. 57). They also occur on a branch from 

 the filament which gives rise to the archegonia ; when they are 

 borne on a separate filament they are generally formed in larger 

 quantities. The cells of a filament which give rise to the anthe- 

 ridial clusters are often broader and sometimes shorter than the 

 ordinary cells. 



. . The antheridium is formed by a cell of a filament sending out a 

 cell which divides by a partition wall near the apex (Figs. 49, 50). 

 This apical cell enlarges and soon cuts off another cell by a wall 

 parallel with the first (Fig. 51). This small cell does not elongate 

 but always remains short and forms the pedestal for the antherid- 

 ium ; the apical cell becomes large and globular and cuts off a 

 cap cell at the summit, with the wall oblique (Fig. 52) ; the large 

 cell divides up into the mother cells of the antherozoids (Figs. 

 52, 53, 54) and one ring cell. In some cases there appear to be a 

 single layer of two or three peripheral cells. The ring cell (or 

 cells) contain chlorophyl though they lose this before the anther- 

 ozoids are matured. Dehiscence takes place by the swelling of the 

 ring cell and the rupture of the cap cell. The antherozoids appear 

 to be surrounded by a very fine membrane when they escape from 

 the antheridium (Fig. 55); they are spirally coiled, with cilia at 

 their anterior ends. Very few ripe antheridia were found. The 

 antherozoids do not seem to be produced in large quantities. 



Archegonia 



The archegonia occur nearer the base of the filaments than the 

 antheridia (Fig. 57) on cells of the filaments which have become 

 more than one cell wide through division. They generally bear 

 the same relation to the original cell of the filament as do the 

 branches from other cells ; they are borne singly or in pairs (Fig. 

 6$) 9 sometimes in groups of three or four (Fig. 58) often on both 

 sides of the protonema. One filament was found which gave rise 

 on six consecutive cells to two archegonia each ; two cells above 



