318 
PLANT STUDIES 
contain both kinds, for Mosses are both dioecious and monoe- 
cious. The two principal groups are as follows : 
207. Sphagnum forms. These are large and pallid bog 
mosses, found abundantly in marshy ground, especially of 
temperate and arctic regions, and are conspicuous peat- 
B C D i E r A 
FIG. 291. Sphagnum : A, a leafy branch (gametophore) bearing four mature sporo- 
gonia ; J5, archegonium in whose venter a yonng embryo sporophyte (em) is de- 
veloping ; C, section of a young sporogonium (sporophyte), showing the bulbous 
foot (spf) imbedded in the apex of the pseudopoditim (ps}, the capsule (k), the 
columella (cd) capped by the dome-shaped archesporium (spo), a portion of the 
calyptra (cd), and the old archegonium neck (ah) ; />, branch bearing mature 
sporogonium and showing pseudopodium (ps), capsule (k), and operculum (d) ; 
E, antheridium discharging sperms ; F, a single sperm, showing coiled body and 
two cilia. After SCHIMPER. 
formers (Fig. 291). The leaves and gametophore axis are 
of peculiar structure to enable them to suck up and hold a 
large amount of water. This abundant water-storage tissue 
and the comparatively poor display of chlorophyll-contain- 
ing cells gives the peculiar pallid appearance. 
208. True Mosses. This immense and most highly organ- 
ized Bryophyte group contains the great majority of the 
