PERIOD V. 1803-1846 IS 



to Schweinitz, a Moravian brother, who moved from one country to another, 

 working and pubhshing, now in America and now in Europe. His name is 

 however chiefly associated with fungi. Later American Hchenology is 

 nobly represented by Tuckerman' who issued his first work on lichens in 

 1839, and who continued for many years to devote himself to the subject. 

 He followed at first the classification and nomenclature that had been 

 adopted by F6e, but as time went on he associated himself with all that was 

 best and most enlightened in the growing science. 



Travellers and explorers in those days of high adventure were constantly 

 sending their specimens to European botanists for examination and deter- 

 mination, and the knowledge of exotic lichens as of other classes of plants 

 grew with opportunity. Among the principal home workers in foreign 

 material, at this time, may be cited Fee^ who described a very large series 

 on officinal barks {Cinchona, etc.) so largely coming into use as medicines ; 

 he also took charge of the lichens in Martius's^ Flora of Brazil. Montagne* 

 named large collections, notably those of Leprieur collected in Guiana, and 

 Hooker' and Walker Arnott determined the plants collected during Captain 

 Beechey's voyage, which included lichens from many different regions. 



G. Period VI. 1846-1867 



The last work of importance, in which microscopic characters were 

 ignored, was the Enumeratio critica Lichenum Europaeum by Schaerer", a 

 veteran lichenologist, who rather sadly realized at the end the limitations 

 of that work, as he asks the reader to accept it " such as it is." Many years 

 previously, Eschweiler'' in his Systema and F6e' in his account of Cryptogams 

 on Officinal Bark, had given particular attention to the internal structure as 

 well as to the outward form of the lichen fructification. F^e, more especially, 

 had described and figured a large number of spores; but neither writer had 

 done more than suggest their value as a guide in the determination of genera 

 and species. 



It was an Italian botanist, Giuseppe de Notaris", a Professor in Florence, 

 who took up the work where Fee had left it. His comparative studies of both 

 vegetative and reproductive organs convinced him of the great importance 

 of spore characters in classification, the spore being, as he rightly decided, 

 the highest and ultimate product of the lichen plant. In his microscopic 

 examination of the various recognized genera, he found that while, in some 

 genera, the spores conformed to one distinct type, in others their diversities 

 in form, septation or colour gave a decisive reason for the establishment of 

 new genera, while minor differences in size, etc. of the spores proved to be of 

 great value in distinguishing species. The spore standard thus marks a new 



' Tuckerman 1839. ^ F^e 1824. ' Martius 1833. •" Montane 1851. ' Hooker 1841. 



* Schaerer 1850. ' Eschweiler 1824. * Fee 18.24. ' De Notaris 1846. 



