CLASS MTJSOI. 

 SUB-CLASS I. SPHAGNALES. 



Spores not developed from the Endothecium, but from a 

 distinct layer of cells, the Amphithecium. Columella developed 

 from the Endothecium, not penetrating the spore-bearing layer. 

 Capsule opening by a lid. 



Order I. SPHAGNACEvE. 



The Sphagnaceae differ so widely from the rest of the mosses 

 . that they are by many authorities not even considered to be mosses 

 at all in the strict sense of the word. In the fasciculate arrange- 

 ment of the branches, in the cell structure of the leaves, and in the 

 absence, except in the young state, of rootlets, their vegetable 

 morphology has no parallel among the mosses, while the struc- 

 ture of the reproductive organs, both male and female, serves 

 still further to widen the gap. 



If, however, the differences which separate them from the 

 other mosses are striking, the points of resemblance are no less 

 so, and a work which treats of the mosses in general and omits 

 the Sphagnaceae, can hardly avoid giving a sense of incomplete- 

 ness. 



The plants belonging to this order are comprised within 

 a single genus. They are usually found in dense masses or 

 cushions in bogs or on wet moorlands, where they often form the 

 prevailing and the distinctive feature of the vegetation ; more 

 rarely on the brink of mountain streams or in the clefts of 

 rocks. 



The stem is usually erect and thread-like, the erect position 

 being only maintained by the crowded condition of the plants. It 

 is composed of two forms of tissue, a central cylinder or axis, 

 usually coloured, and having the outer layers of its cells often 

 more or less tough and hard ; this is surrounded by a cuticular 

 sheath of from one to four layers of larger hyaline cells with thin 

 walls; these, however, are not always easily distinguishable 

 from the outer layers of the central axis. The cuticular sheath 

 B 



