THE BRYOPHYTES 



277 



note the pointed foot which was imbedded in the gametophyte 

 (Fig. 200). 



Study young and full-grown sporophytes and note : 



(a) The slender stalk. 



(b) The enlarged capsule. 



(c) The hood or calyptra which covers the young capsule. Cut- 

 ting ofE and mounting in water the ends of ca|:isules of various ages, 

 examine with m.p. and note: 



(d) The lid covering the 

 mouth of the capsule. 



(e) The fringe of teeth 

 at the mouth. How many 

 rows are there? 



(/) The spores (best seen 

 with h.p.). 



Draw the structures 

 above described (a-f). 



357. Discussion. — 



The leafy moss-plant, 

 or gametophyte, is more 



all*.--- f?«^^ 



0.^^ 



.^^ 





Fig 



^^"^opWe 



203. Diagram of Life History 

 of a Moss. 



highly Oro-anizecl than ^'*>aiitlieridium;^lr, archegonium; s, sperm; 

 , T *' , -.r e, egg-cell; e', egg. 



such liverworts as Mar- 



chantia, since the moss has well-differentiated stems and 

 leaves. It is also more specialized even than liverworts 

 which bear leaves, since the moss stem has a more compli- 

 cated structure than that of any leafy liverwort. 



The sporophyte of mosses is more highly developed 

 than that of most liverworts and far more so than the 

 Marchantia sporophyte. The elevated position of the cap- 

 sules and the expansion of the fringe of teeth at the mouth 

 of each capsule assist in dispersing the spores. Although 

 the sporophyte has some stomata and can do a little photo- 

 synthetic work, it must draw its supply of water and min- 

 eral matter from the leafy stem out of which it springs. 



