IOWA ACADEMY OF SCIENCES. 
17 
These being the first really important works by an Ameri- 
can, it will be seen that from 1810 to 1847 we were emerg- 
ing somewhat from the influence of Europe, and the time 
included between these two dates we may appropriately 
regard as The Euro- American Period of American lichen- 
ology. In 1888, two years after the death of the author, 
appeared the second volume of Tuckerman’s “ Synopsis 
which closed the work of this great Lichenist. From 1847 
to 1888 the influence of the one man, Tuckerman, was 
plainly to be seen upon nearly all of the work done in 
American Lichenology, and we may consider this time as 
The Tuckermanian Period. It is not to the discredit of 
Tuckerman that we are pleased to record that since his 
death there has been a gradual breaking away from ideas 
held by him and his co-workers as to the nature and proper 
classification of lichens, and since we are in want of a 
better name, we may call the time subsequent to 1888> 
The Recent Period of American lichenology. The change 
going on is perhaps most plainly outlined in Schneider’s 
“ Text-Book ” and in his more elementary “ Guide”, but it 
is apparent also in some papers published in the present 
decade, and a considerable amount of material still in 
manuscript will, it is hoped, bring needed changes in syn- 
onomy, description of the species and classification. 
THE PERIOD OF BEGINNINGS (FROM THE BEGINNING TO 1810 .) 
If we compare the outline of American lichenology sug- 
gested above with that previously given for Europe, it ap- 
pears that the date, 1810, taken as the close of our first 
period, is only eight years later than that which closes the 
fourth of Krempelhuber’s periods. Comparing a little 
further, we find that the date of the first definite and certain 
mention of a North American lichen, 1703, is just nine 
years after the close of the first of Krempelhuber’s periods. 
Thus it seems that the work on lichens began in our land 
as soon as these plants were recognized as distinct from 
mosses, algae and fungi, and at a time when only about 
75 lichens were known — possibly 100. Botanical w 7 ork 
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