SECT. I 



CRYPTOGAMS 



Cliara fmijilis, a very common species, may be taken as a type of the Characcac. 

 In this instance the sexual organs are produced in pairs on the nodes of the short 

 branches, the antheridium is directed downwards, and the oogonium upwards (Fig. 

 264, B). The antheridium has a complicated structure, and in this respect exhibits 

 a higher stage of development than the similarly named organs of the Mosses and 

 Vascular Cryptogams. The antheridium is attached to the node of the fertile branch 

 by a stalk-cell {A, p) and a basal nodal cell (mas). The antheridium has the form of a 

 hollow sphere, the wall of which consists of eight flat cells termed shields. The 



& 



Fig. 264. — Cham fnuj His. A, Median longitudinal section through a lateral axis r, and the sexual 

 organs which it bears ( x 90) ; a, antheridium borne on the basal nodal cell nix, by the stalk - 

 cell p ; m, manubrium; ob, an oogonium; no, nodal cell; po, the stalk-cell; v, pivotal cell; 

 c, the crown. B, a lateral axis bearing axes of the third order ( x 6) ; a, antheridium ; 

 o, oogonium. 



four uppermost shields are triangular ; the lower four, in consequence of their 

 insertion on the stalk-cell, are trapeziform in shape. It is to the presence of red 

 chromatophores in the shields that the red colour of the antheridia is due. In 

 cross-section (Fig. 264, A, a) the walls of the antheridia seem to be composed of 

 many cells in consequence of the apparent segmentation of the shields by the 

 radial infolding of their walls. From the middle of the inner wall of each shield a 

 cylindrical cell called the manubrium (m) projects inwards towards the centre of the 

 antheridium. Each manubrium terminates in a knob-like cell or oapitulum, from 

 which a large number of long simple filaments composed of short cells grow out 

 into the cavity of the antheridium. The spermatozoids are produced in the cells of 

 these filaments ; in each cell only one, but collectively comprising an enormous 

 number (as many as 40,000 in one antheridium). The spermatozoids make their 



