TAXONOMY 
285 
body into distinct stem and simple leaves, and the formation of the 
sexual organs at the end of an axis of a shoot. They are either monoe¬ 
cious, when both kinds of sexual organs are borne on the same plant, 
Fig. 154. —Hair-cap moss (Polytrichum commune). A, male plant; B, same, 
proliferating; C, female plant, bearing sporogonium; D, same; g, gametophyte; s, 
seta; c, capsule; o, operculum; a, calpytra; E, top view of male plant. {Gager.), 
9 
