CH. X] 



ANTHERIDIUM. 



135 



When the archegonium is fully ripe the canal-cells 

 break down into mucilage, which swells and bulges out at 

 the opening now formed at the free end of the canal by 

 the separation of the terminal tier of cells. 



The anther idia (fig. 61) are small green papillae (which 

 afterwards become brown) found principally among the root- 

 hairs, and further from the notched end of the prothallus 



B C 



FIG. 61. 



A. MATURE ANTHERIDIUM OF A FERN (Polypodium) AND CONTAINING 

 NUMEROUS MOTHER-CELLS OF ANTHEROzoiDS. Chloroplasts are visible 

 in the cells constituting the wall of the antheridium. 



B. AN ANTHEROZOID. 



C. THE ANTHERIDIUM BURST AND EMPTY. 



(After Strasburger.) 



than are the archegonia. Their architecture is very re- 

 markable. Each antheridium is built of three cells : one 

 forms the roof, and the remainder form the circular walls 

 which limit the cavity within. Imagine a. piece of india- 

 rubber tubing bent into a ring by the union of its ends : 

 if such a ring be placed on the table it will make a low 

 circular wall which may be doubled in height by the 

 superposition of another similar ring. This is precisely the 

 structure of the antheridium, its wall is made up of two 

 hollow, ring-like cells with a third flat cell on the top. 



