DIV. I 



BRYOPHYTA 



477 



The ANTHERIDIA (Fig. 433) or male sexual organs are stalked, 

 ellipsoidal, spherical, or 

 club-shaped, with thin /~~\ 

 walls formed of one layer AT 

 of cells and enclosing 

 numerous small, cubical 

 cells, each of which 

 becomes divided diagon- 

 ally or transversely into 

 two sperma tozoid 

 mother cells ( w ). At 

 maturity the sperm a to- 

 zoid mother cells separ- 

 ate and are ejected from 

 the antheridium, which 

 ruptures at the apex. In 

 the case of the Musci 

 there is a terminal group 

 of one or more cells with 

 mucilaginous contents 

 which on swelling burst 

 the cuticle (Fig. 438 A) 



Fi<;. 434. Development of the antheridium in Fegatdla conica, 

 one of the Marchantiaceae. A, Unicellular stage. E, The 

 stalk-cell (st) cut off. C, D, Antheridium divided into a 

 row of cells which in turn are divided by longitudinal 

 walls. E, Cutting off of the layer of cells to form the wall 

 (w). F, Advanced stage of development. (A-E x 400 ; 

 F x 220. After BOLLETER.) s 



111 



the Liverworts the mucilaginous cells 

 separate irregularly from one another 

 and there is no denned cap of cells. 

 By the dissolution of the enveloping 

 walls of the mother cells the sperma- 

 tozoids are set free as short, slightly- 

 twisted filaments, bearing two long 

 cilia close to the anterior end (Fig. 

 433). 



The antheridium is developed from a 

 single superficial cell ; it is only in the 

 case of Anthoceros (Fig. 443) that it is 

 formed endogenously. In the lower Liver- 

 worts (Marchantiales) this cell becomes 

 divided into transverse disc-shaped seg- 

 ments ; each of these is divided by walls 

 at right angles into four cells, and then 

 Fio. 435. Development of the antheridium of tangential walls in these quadrants separate 

 a Moss. Funaria hygrometrica. A Primor- the peripheral cells of the antheridial wall 

 dinm of an antheridium divided into four h internal cells, which give rise 



cells. B, Formation of the apical cell from "I 



the uppermost cell. C, Division of the apical to" the spermatogenous tissue (Fig. 434 

 cell. D, The separation of the wall-layer and A-F]. In the higher Liverworts (Junger- 

 the cells that will give rise to the spermato- rnanniales) the original cell is first divided 

 genous tissue. E, Same stage in transverse iuto ft rQW of three b transverse walls ; 

 section. F, Older stage. (After D. CAMPBELL.) .. , : . ., , ,. , 



the uppermost cell divides by a vertical 



wall, and in each of the two resulting cells two successively-formed walls separate 



