BRYOPHYTES 



"3 



initial. The mature archego- 

 nium is stalked, with a massive 

 venter, a long and often twisted 

 neck, and numerous neck canal 

 cells (fig. 249). 



Sporophyte. — The sporophyte 

 (fig. 250) develops at first by a 

 series of transverse walls until a 

 short filament is formed, which 

 later becomes massive by means 

 of vertical walls. The upper tiers 

 develop the capsule, which is 

 organized as in Anthoceros, with 

 the endothecium developed as 

 the axial columella, with the 

 sporogenous tissue cut ofif as an 

 inner layer (becoming four 

 layers) of the amphithecium 



Fig. 248. — Sphagnum: stem bearing a 



and capping the columella like terminal cluster of sporophytes, showing the 



a dome, and with a wall of five P°='''°" °^ archegonia. 

 to seven layers. These Anthoceros-\W.e features are further emphasized 

 by the large bulbous foot and the rudimentary seta, which is only a 



necklike connection between capsule and 

 foot, and is often called the neck. Very 

 important differences, however, are as 

 follows: (i) there is no such development 

 of chlorophyll tissue in the wall of the 

 capsule as characterizes 4 n//ioce/'05; (2) the 

 neck is not a growing region, and hence 

 the capsule does not elongate ; and (3) the 

 caps ule dehisces by a definite lid {oper- 

 culum), which is distinctly a moss character. 

 As in all bryophytes, during the develop- 

 ment of the sporophyte the venter of the 

 archegonium develops the encasing calyptra, 

 which in Sphagnum is ruptured by the 



Fig. 249. — Sphagnum: sur- 

 face view of three archegonia; 



the middle archegonium shows growing capsule. 

 the spiral direction of the cell 

 rows of the neck. — After 



ScHiMPER. pseudopodium, which is a structure replac- 



A pecuhar iea.ti\re oi Sphagnum i£_Jthe 



