184 A TEXT-BOOK OF BOTANY 



(5) Appearance of leaves. Among the Bryophytes very 

 simple leaves are developed by the gametophyte, and the 

 mosses produce leaves upon an erect stem. 



(6) Many-celled sex-organs. The many-celled antheridia 

 and flask-shaped archegonia are very characteristic of Bryo- 

 phytes, and distinguish even the thallose forms from any 

 Thallophytes. 



107. General characters of Ferns. The ferns are well- 

 known plants, and the ordinary forms are easily recognized 



FIG. 176. Shield ferns. 



(Fig. 176). In fact, the general appearance of the large 

 compound leaves is so characteristic that when a leaf is said 

 to be fern-like a particular appearance is suggested. Al- 



