mr 



CHAPTER XXI 

 TYPES OF CRYPTOGAMS; BRYOPHYTES 



334, The Group Bryophytes. Under this head are 

 classed the liverworts and the mosses. Both of these 

 classes consist of plants a good deal more highly organized 

 than the thallophytes. 

 Bryophytes have no 

 true roots, but they 

 have organs which 

 perform the work of 

 roots. Some of them 

 have leaves (Fig. 206), 

 while others have 

 none (Fig. 201). 

 Fibro - vascular bun- 

 dles are wanting. The 

 physiological division 

 of labor is carried 

 pretty far among all 

 the bryophytes. They 

 have special appara- 

 tus for absorbing 

 water and sometimes 

 for conducting it 

 through the stem; stomata are often present and some- 

 times highly developed. There are chlorophyll bodies, 

 often arranged in cells extremely well situated for acting 



277 



FIG. 201. Part of Male Thallus of a Liverwort 



(Marchantia disjuncta). (Enlarged.) 



mr, male receptacle. 



