i88 



MOSSES AND FERNS 



CHAP. 



Whether the first antheridium, as in Andrecea and Fontinalis, 

 arises from the apical cell is doubtful, and it is impossible to 

 trace any regularity in the order of formation of the very 

 numerous antheridia. Except in very old plants, all stages 

 of development are found together, and the history of the 

 antheridium may be easily followed. A superficial cell projects 

 above its neighbours, and this papilla is cut off by a transverse 



Fig. go. — Funaria hygrometrica (Sibth.). Development of the antheridium. A-D, Longitudinal 

 sections of young stages, X 600 ; D is cut in a plane at right angles to C ; E, optical section of 

 an older stage, X300; G, F, cross-sections of young antheridia, x6oo; H, diagram showing the 

 first divisions in the antheridium ; I, young spermatozoids, X 1200. 



wall. The outer cell either becomes at once the mother cell of 

 the antheridium, or other transverse walls may occur, so that a 

 short pedicel is first formed (Fig. 90, A). Finally in the 

 terminal cell, as in Andre£Ea^.:\.vjo intersecting walls are formed 

 enclosing a two-sided apical cell, from which two ranks of 

 segments are cut off in regular succession (Figs. A, B, C). The 

 number of these segments is limited, in Fuiiai'ia not often 

 exceeding seven, and after the full number has been formed, the 



