THE MOSS FAMILY. 



491 



The great characteristic of the mosses is their fructification, which 

 some observers believe to be assuredly male and female, and it is not 

 to be denied that there is a striking semblance of sexes, if not the 

 reality. The supposed male flowers are microscopic vesicles called 

 " antheridia," surrounded by several rows of spreading leaves called 

 the "perigonium." The supposed female flowers, called " archegonia," 

 consist of slender flask-shaped bodies, surrounded by a cluster of erect 

 leaves, the latter called the " perichaetium." In due process of time 



Fig. 221. 

 Hypnum tamariscinum (Fern-moss). 



after evolution one of these " archegonia " becomes a theca, which is 

 generally elevated upon a long and slender stalk, the remainder of the 

 "archegonia" undergoing no change, and being found, in an abortive 

 state, attached to the base of the stalk of the perfected one. The 

 theca is generally urn-shaped, sometimes globular, and either erect, 

 more or less curved sideways, or quite pendulous. (Fig. 220.) While 

 young, the incipient stalk and theca are enveloped in a thin film of 

 cellular tissue. As the former lengthens itself, this envelope becomes 



