MUSCI 



155 



frill to the base of the sporange, which dehisces by a transverse slit near 

 the apex, detaching a strongly convex opercule. There is no peristome 

 nor annulus. A portion of the contents of the sporange remains un- 

 differentiated in the form of a low columel not reaching to the apex. 

 The remainder is converted into spores, which differ from those of other 

 mosses in being of two kinds, megaspores and microspores (see fig. 125). 

 According to Warnstorf (' Hedwigia,' 1886, p. 89 ; and ' Verhandl. Bot. 





FIG. 130. S. acutifolium. A, male branch, 

 with leaves removed to expose antherids, 

 a (magnified). B, antherid (more highly 

 magnified) dehiscing. C, antherozoid (still 

 more magnified). (After Schimper.) 



FIG. 131. A, S. acutifolium, section of female 

 inflorescence ; ar, archegones ; ch, pericha;tial 

 leaves. B, longitudinal section of sporogone, sg ; 

 ar, archegone ; c, calypter ; sg 1 , foot ; v, vagine ; 

 ps, pseudopode. C, S. squarrosum Pers. ; sg, 

 sporogone ; d, opercule ; c, ruptured calypter ; 

 gs, pseudopode ; ch, perichsetial leaves (magni- 

 fied). (After Schimper.) 



Verein,' Brandenburg, 1886, p. 181), these two kinds of spore are found 

 either in the same or in different sporanges ; the diameter of the former 

 varies between 30 and 33 mm., that of the latter between 12 and 18 mm. 

 The megaspore is by far the most common form, and its germination only 

 has at present been observed. Warnstorf suggests that the two kinds are 

 sexually differentiated, the megaspores giving rise to a female, the micro- 

 spores toamaleprothallium, as in the Heterosporous Vascular Cryptogams. 



