CnVPTOGAMIA. 491 



branch of physiology- He examiaed all that 

 had Ix'en done bi'fore his tiine,,det(3cted 

 the truth, raised mosses from aeed, /'. 193 — 

 39*>->\ tuid f.stahiished tlieir characters on the 

 principles we havfe^ already explained. 



The Linnaian genera of jMosses are chiefly 

 founded on the situation of the capsule, 

 whether lateral or terminal, with some other 

 cu'cuinstances. They are too few, and not 

 strictly natural. Heclwig first brought into 

 notice the structure of the fringe, perkto- 

 inium, which in most mosses borders the 

 orifice of the capsule. This is either simple, 

 /. 189 b, or double, /: UVo, 214, and con- 

 sists either of separate teeth, or of a plaited 

 and jagged membrane. The external fringe 

 is mostly of the former kind, the inner, 

 when present, of the latter. The number 

 of teeth, remarkably constant in each ge- 

 nus and species, is either 4, 8, 10, 32 or 

 64. On these therefore Hedwig and his 

 followers have placed great dependence, 

 only perhaps going into too great refine- 

 ments relative to the internal fringe, \\hH'h 

 is more difhcult to examine, and less cer- 

 tain, than the outer. Their great error 



