28 



POPULAR HISTORY OP LICHENS. 



[of date 1831], and the 'Enumeratio Critica Lichenum Eu- 

 ropseorum' of Schserer [published so lately as 1850], — the 

 most valuable works for a description of European Genera and 

 Species to which we can refer the student. It is only within 

 the last few years that the minute anatomy and physico-che- 

 mical characters of the vegetative and reproductive cell-sys- 

 tems of the Lichens have attracted the attention of botanical 

 microscopists. In Germany, a host of monographers, such 

 as Itzigsohn, Bayrhoffer, Rabenhorst, Von Elotow, and Von 

 Holle ; in France, Tulasne and Montague ; in Russia, Buhse ; 

 and in England Leighton, have recently published valuable 

 contributions to this branch of Lichenology, — contributions 

 which have placed the Lichens, in point of anatomy and 

 physiology, on at least an equal footing with other Crypto- 

 gamic families, to which they have hitherto been considered 

 far inferior in the scale of vegetation. But the most im- 

 portant monograph ever published on this subject is un- 

 questionably that of Tulasne, — his ' Memoire pour servir a 

 THistoire Organographique et Physiologique des Lichens/ 

 published in the ' Annales des Sciences Naturelles/ in 1852. 

 This author apparently sets at rest the long debated ques- 

 tion of the reproduction of Lichens, by describing the mi- 

 nute anatomy of organs which must now be generally con- 



