14 THE CHICAGO ACADEMY OF SCIENCES. 



He made no use of the spores and thekes in his classification. The 

 system he founded was long used and made his name immortal. 

 In 1831, Elias Fries, the great Swedish botanist, published the 

 Lichenographia Europea Reformata, and gave utterance to views 

 that have influenced all later studies of the greatest students 

 of lichens. He divided them into eight tribes, of which five now 

 stand as given elsewhere. He also made further divisions which 

 subsequent writers changed or assumed. The views of Fries were 

 so far in advance of others and his work as a systematist so highly 

 regarded, that Tuckerman referring to the advances made in the 

 study of lichens, says: " The whole movement took its start from 

 the results gained by the unsurpassed penetration of Elias Fries." 



But the period was a golden one and prolific of eminent 

 botanists — Nylander, Eschweiler, Fee, Wallroth, Schaerer, Mon- 

 tague and Floerke, all systematists. There were also many others 

 of great eminence in Lichenology. Of the above Dr. William 

 Nylander, who still survives, is the most celebrated. He has 

 not only published many philosophic papers and works, but has 

 described more new species than any other man, and his knowledge 

 of lichens exceeds that of all others. Dr. J. MuUer is hardly less 

 distinguished, however, while Dr. Minks, and Schwendener, have 

 achieved renown by wonderful discoveries as to the anatomy and 

 growth of lichens, which, if they are confirmed, will overturn all 

 previous theories. From what has been stated it will be seen that 

 Europe had monopolized the field of study, and naturally enough, 

 for America was young. 



It was at such a time that Tuckerman, who had turned early to 

 the investigation of lichens, became an earnest student of the 

 great European botanists, particularly of Acharius, Fries and 

 Nylander. Assisted in the field by several enthusiastic workers, 

 portions of New England were explored and the lichen-flora 

 studied and made known to the world. As his views enlarged 

 he gradually came to have conclusions of his own as to the 

 systematic arrangement of the species in harmonious and natural 

 relations with each other. The great Swede seems to have 

 been his guide in part, while Nylander was not disregarded, nor in 

 later years the new discoveries of Minks, Tulasne, Bayerhoffer and 

 others. Tuckerman was pre-eminent as a systematist, and the full 

 elucidation of his views will be found in his works — The Lichens of 

 California, 1866; General Lichenum, 1872; and his Synopsis, 



