CRYPTOGAMIA. 375 



either 4, 8, 16, 32 or 64. On these therefore Hed- 

 wig and his followers huve placed great dependence, 

 only perhaps going into too great refinements relative 

 to the internal fringe, which is more difScult to exam- 

 ine, and less certain, than the outer. Tiieir great er- 

 ror has been laying down certain principles as absolute 

 in forming genera, without observing whether aii such 

 genera were natural. Such mistakes are very excus- 

 able in persons not conversant with botany on a gen- 

 eral scale, and whose minute and indefatigable atten- 

 tion to the detail of their subject, more than compen- 

 sates the want of what is easily supplied by more 

 experienced systematics. Thus Barbula of Hedwig 

 is separated from Tortida, Engl. Bot. t. 1663, and 

 Fissidens from Dicranum^ t. 1272, 1273, on account 

 of a diiference of form or situation in the barren flow- 

 ers, which is evidently of no moment, and merely di- 

 vides genera that ought to be united. The same may 

 be said of genera founded on the union of the stamens 

 and pistils in one flower. On this subject J have 

 been more diffuse in a paper on Mnhim, in TV. of 

 Lhin^ Soc. V. 7, 254, to which I beg leave to refer 

 those who are desirous to study it further. Various 

 and abundant specimens of this tribe of plants, show- 

 ing the various structure of the fiingc, lid and other 

 parts, may be seen in the latter volumes of English 

 Botany more especially. 



Mosses are found in the hottest and coldest cli- 

 mates. They are extremely tenacious of life, and, 

 after being long dried, easily recover their health and 

 vigour by moisture. Their beautiful structure can- 



