MOSSES, LIVERWORTS, AND FERNS 



265 



egg, where one of them unites with the egg, thus producing 

 an obspore, or sex spore. 



The oosporejloes not have a resting period, as in Vaucheria, 

 but begins its growth almost immediately when formed. It 

 enlarges, divides into many cells (that is, it grows), and soon 

 "elongates Into a stalk one end of which is attached to the old 



D 



FIG. 204. Reproductive organs of moss 



A, an antheridium containing the mother cells (m) of the sperms ; the cap (c) later 

 opens to allow exit of sperm mother cells ; B, one sperm ; (7, a diagram showing 

 the relations of antheridia (an) and archegonia (ar), and the leaves (f; on the tip of 

 the shoot; D, an archegonium with the egg (e), the neck (n), and the mucilagin- 

 ous mass (m) through which the sperms pass to reach the egg. All are the moss 

 Atrichum undulatum. From Bonnier and Sablon 



leafy stalk, and the other extends up above the leaves. The 

 stalk which grows from the oospore bears chlorophyll. A cap- 

 sule is produced at the tip of this new stalk, and spores are 

 formed by the division of part of the inner tissues of the cap- 

 sule. Since these spores are formed by division of tissues and 

 not by union of cells, it is obvious that they are asexual spores. 

 When they fall to the ground, they produce protonema again, 

 and thus begin another life round of the moss plant. The 



