THE ARCHEGONIAT^E 



231 



of a flower. This is especially noticeable in the antheridial recep- 

 tacles of some Mosses, like Polytrichum and Funaria. In Sphagnum 

 the antheridia are borne singly in the axils of closely imbricated 

 leaves which are red or yellow in color, so that the antheridial 

 catkin-like shoots are very noticeable. 



The Sporophyte. The sporophy te in the higher Mosses becomes 

 highly specialized, but in all but Sphagnum the development in the 

 earlier stages is uniformly the same. 



Sphagnum. The embryo of Sphagnum resembles very much that of the 

 Anthocerotales, and suggests an affinity with that group. The young embryo 

 (Fig. 203) shows the formation of several tiers of cells, and an early differentia- 



Flo. 194. Funaria hygrometrica. Development of the archegonium. B, optical 

 section; F, surface view; the others longitudinal sections. G, paraphyses. 

 ( F, X 150 ; the others, X 400) . x, apical cell. 



tioii of endothecium and amphithecium. As in the Anthocerotales, the arche- 

 sporium is derived from the amphithecium, in which respect Sphagnum differs 

 from all the other Musci. The archesporium extends over the top of the colu- 

 mella as it does in Anthoceros. 



The basal growth of the young sporophyte is limited, and at maturity it is a 

 globular or oval capsule, with a large foot imbedded in the end of the gameto- 

 phoric shoot. Stomata are developed in the epidermis of the capsule, which 

 opens by a circular lid. 



Bryales. In the typical Mosses (Bryales) the embryo (Figs. 195, 196) first 

 divides by a transverse wall into two nearly equal cells. In the upper (epi- 

 basal) half, the next walls are inclined and a large two-sided apical cell is 

 formed, which continues to divide for a long time, and causes a rapid increase in 

 length of the embryo, which becomes spindle-shaped. Later the apical growth 



