THE GREAT GROUPS OF BRYOPHYTES 



123 



105, /)), which means a "cover" or "lid." This may 

 serve to illustrate what is called an "intermediate" or 

 "transition" type, Sphagnum showing characters which 

 ally it to Anthoceros forms on the one side, and to true 

 Mosses on the other. 



A peculiar feature of the sporogonium is that it has no 

 long stalk-like seta, as have the true Mosses, although it 

 appears to have one. This false appearance arises from the 



B D I E r A 



FIG. 105. Sphagnum : A, a leafy branch (gametophore) bearing four mature sporo- 

 gonia; B, archegonium in whose venter a young embryo sporophyte (em) is de- 

 veloping; C, section of a young sporogonium (sporophyte), showing the bulbous 

 foot (spf) imbedded in the apex of the pseudopodium (ps), the capsule (k), the 

 columella (co) capped by the dome-shaped archesporium (spo), a portion of the 

 calyptra (ca), and the old archegonium neck (ah)\ D, branch bearing mature 

 sporogonium and showing pseudopodium (ps), capsule (k), and operculum (d); E, 

 antberidium discharging sperms; F, a single sperm, showing coiled body and two 

 cilia. After SCHIMPER. 



fact that the axis of the gametophore is prolonged above 

 its leafy portion, the prolongation resembling the seta of 

 an ordinary moss (Fig. 105, D). This prolongation is 



