3?() CKYPTOGAMIA. 



Order, comprehended by Linnaeus under one genus 

 by the name of Lichen, the fructification of which, 

 for the most part, consists of a smooth round disk, 

 J\ 198, Mat, convex, or concave, with or without an 

 adventitious border, in the substance of which disk 

 the seeds are lodged. In some others they are 

 placed in powdery warts, or in fibrous receptacles. 

 The barren flowers are supposed to be powdery 

 also,/. 197, very much like those of Jungermnnnia. 

 See EngL Bat. t. 126, and various other parts of 

 that work, where a great number of species are 

 figured. The whole tribe has been much investi- 

 gated, and attempted to be divided into natural 

 genera founded on habit, by Dr. Hoffmann of 

 Gocttingen, whose figures are perfect in their kind. 

 Hut a more complete scheme for reducing this 

 family to systematic order has been made known 

 to the world by Dr. Acharius, a learned Swede, 

 who in his Prodromus, and Mcthodus Lichenum, 

 lias divided it into genera founded on the receptacle 

 of the seeds alone. Hence those genera, though 

 more technical, arc less natural than Hoffmann's ; 

 but they will, most likely, prove the foundation of 

 all that can in future be done on the subject, and 

 the works of Acharius form a new a?ra in crypto- 

 gamic botany. It is only perhaps to be regretted 

 that he has been somewhat too prodigal of new 

 terms, which when not wanted are always a burthen 

 to science, and rather obscure than illustrate it. 



