262 



MUSCI. 



antheridia and archegonia, analogous (though different in 

 structure) to those of Ferns, are developed. Hence, 

 unlike the preceding groups of Cryptogams, the vegeta- 

 tive generation, or Moss-plant, is at the same time the 



FIG. 204. Hair-Moss : a, seta bearing a sporange ; b, spprange covered by 

 its calyptra ; c, head of antheridia, forming the male inflorescence. 



sexual generation. From the archegonia, fertilized by 

 the spiral antherozoids of the antheridia, arise the 

 sporanges, usually bom up by a slender peduncle (the 

 seta), and capped by the upper portion of the arche- 

 gonium, which is torn away by the rising sporange for 

 which it forms the calyptra. The sporange, with its 

 appendages, and seta when present, constitutes the asexual 

 generation of the Moss cycle. Mosses, therefore, as 

 compared with the foregoing Orders of Cryptogams, are 

 specially remarkable in the predominance, both in relative 

 bulk and duration, of the sexual generation. 



Other British Mosses differ in the position of the seta, in 

 themodeofopeningofthe sporange, the presence or absence 

 of a peristome which, moreover, is of various origin in dif- 

 ferent genera, and the number of teeth which compose it, &c. 



In Mosses, vessels are absent from both stem and 

 leaves ; hence they together with the plants grouped 

 under the three following Families, all of which are 



