168 



MUSCINE^E 



stomates belong; (2) a close tissue containing but little chlorophyll, and 

 with the cell-walls pitted or reticulately thickened, without intercellular 

 spaces but sometimes containing mucilage-receptacles j and (3) a ventral 



rlil 



FIG. 153. A, transverse section through middle portion of thallus of M. polymorpha (x 30); B, 

 through marginal portion (more highly magnified). /, colourless layer without intercellular spaces 

 &,. epiderm of upper side ; chl, chlorophyllous layer ; sp, stomate ; s, partition-walls between air- 

 chambers ; ., lower epiderm ; h, rhizoids , b, leaf-like lamellae. (After Goebtl.) 



FIG. 154. Portion of young receptacle of M. polymorpha. A, vertical section; a, epiderm; sfi, 

 stomate ; S, partition-wall separating air-chamber from chlorophyllous cells ; g, mucilage-cell. B, 

 C, young stomate ; po, pore. (After Goebel.) 



epidermal layer, from which spring rhizoids and leaf-like lamellae. The 

 mucilage-passages are especially developed in Fegatella (Radd.) and 



