SYSTEMATIC ARRANGEMENT OF MOSSES. 45 



Where genera approach so near as Trichostomum, Tortula, 

 and some others, different views will be taken by Bryologists. 

 But in whatever way the several species may he grouped, 

 difficulties \\ill arise as to the stability of characters ; and were 

 those and some neighbouring genera again incorporated, there 

 would still be difficulties as to the natural grouping of the 

 species. 



On the whole, the state of Bryology must be considered as 

 extremely imperfect. The entire subject clearly wants the 

 revision of some master-mind. 



