212 MOSSES AND FERNS CHAP. 



as is the case in stomata of the ordinary form. As the stoma 



C* VI II I \'. ^ * 







FIG. 113. Funaria hygromctrica. A, Young; B, older stoma, from the base of the 

 capsule; C, vertical section, Xs6o. 



grows larger, however, the median wall does not grow as fast 

 as the lateral walls, and a space is left between its extremities, 



B. 



FIG. 114. Funaria hygrometrica. A, Part of the peristome; o, an outer tooth; i, one 

 of the inner teeth, X8$; B, section of the seta, X26o; C, cross-section of upper 

 part of calyptra, X525- 



so that the two guard cells have their cavities thrown into 

 communication, and the division wall forms a cellulose plate 



