STRUCTURE OF MOUSES 



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richly branched. The pecuhar habit of these Mosses is partly 

 due to the fact that some of the branches elongate considerably, 

 and hang down alongside the main stem (Fig. 151, F). The 



Fig. 151. — Structure of Mosses. A, Portion of a leaf of the Bog-moss 

 {Sphagnum), showing cells with chloroplasts (ch.) and the large empty 

 cells with their thickenings and pores {p.). B, Leaf-apex of Mniiini, 

 with the midrib {in.). C, Leaf-cells of Hypnum, from the surface, 

 showing thickened walls and pits. D, Transverse section of the stem 

 of JMnium hornum (after Bastit), showing conducting strand {Cs.) and 

 storage-cells (C). E, Leaf-cells of Hylocomium, from the surface. 

 F, Habit of Sphagiuim (after Schimper), showing three sporogonia. 



branching of many prostrate Mosses takes place in a pinnate 

 manner {e.g. Hypmtni, Fig. 150), whilst that of the erect forms 

 is usually forked. Growth of the stem and its branches is 



