IOWA ACADEMY OF SCIENCES. 
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literature, previous to that date. Indeed, this work is 
indispensable to the American iichenist. Likewise, some 
of the European lichenists placed in the next period did 
some work in the present. 
Among American botanists who have contributed to 
our knowledge of lichens, may be mentioned first the 
eminent botanist, W. G. Farlow. Dr. Farlow will not be 
known as a Iichenist especially, but as a student in his 
laboratory I came to know that with his minute knowledge 
of algae and fungi is found also an accurate and wide 
knowledge of our lichens. He has published but few papers 
on lichens, and those that concern our North American 
flora appeared during the present period. 
Turning to men who will be known more especially as 
lichenists, we may consider first the work of Henry Willey. 
After Tuckerman and probably Nylander also, Willey was 
the largest contributor to American lichenology during the 
period. So far as 1 have been able to ascertain, his first 
paper appeared in 1867, and his titles number no less" than 
27. Of these the most important are his “Introduction to 
the Study of Lichens,” 1887; his “Synopsis of the Genus 
Arthonia,” 1890; and his “Enumeration of the Lichens of 
New Bedford,” 1892. The last two works were published 
during the next period, but the work was largely done 
during the period now under consideration. His work on 
the New Bedford lichens is surely the most complete 
survey of a limited area known to American lichenology, 
the whole number of species and varieties resulting from 
thirty years of study coming within a few of 500, of which 
39 were new when found by Willey. His work on Arthonia 
is the only production by an American in the nature of a 
monograph of a lichen genus. The work is a compilation 
of 350 known descriptions of Arthonias, and it scarcely 
reveals the remarkable knowledge of the genus undoubtedly 
possessed by the writer. In order to bring out the feelings 
of Willey regarding the recent ideas as to the nature of 
lichens, I can not refrain from quoting him somewhat at 
length as follows: “I take this opportunity to express my 
regret that the American professors of botany have so 
