CHAPTER XXI 



TYPES OF CRYPTOGAMS; BRYOPHYTES 



334. The Group Bryophytes. — Under this head are 

 cflassed 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 'S Wi/^^Kf^'^^J^il^'^ w 



perform the work of 

 roots. Some of them 

 have leaves (Fig. 206), 

 while others have 

 none (Fig. 201). 

 Fibro- vascular bxm- 

 dles are wanting. The 

 physiological division 

 of labor is carried 

 pretty far among aU 

 the bryophytes. They 

 have special appara- 

 tus for absorbing fig. 201.— Part of Male Thallus of a Liverwort 

 water and sometimes {MarokaUiadisjmicta). (Enlarged.) 



mr, male receptacle, 



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 



