112 BOTANICAL GAZETTE [aveust 
THE SEXUAL ORGANS. 
Cryptomitrium tenerum is monoecious. The antheridia forma 
single row just back of the sporogonial receptacle. They 
are sunk deep in the thallus, and each one is marked on the 
surface by a small conical ostiolum. These ostiola are vey 
inconspicuous, however, and their presence can scarcely be | 
detected with a hand lens. : 
The antheridia are developed before the female receptacle, 
and in Fimbriaria and other allied genera, they are formed on 
dorsal side just back of the apical cell (a, fig. 2). The prim 
a 
Fic. 2.— Antheridia. a, longitudinal section of apex of thallus with 
antheridia ; x, apical cell. X 600. 4, c, d, successive stages of youns 
% 600. ¢, full-grown antheridium. < 480. 
antheridial cell, when it can first be distinguished from so 
cells around it, is a little larger and stains. more deeply 
these cells. The first division (a, fig. 2) 1s transverse 
