14 
IOWA ACADEMY OF SCIENCES. 
of lichens will ever be generally accepted, and the present 
writer is disposed to regard the establishment of a period 
dating from 1894 as at least premature. 
Regarding the early studies in the old w T orld, Theo- 
phrastus, in the third century before Christ, seems to have 
named a number of lichens, giving very crude descrip- 
tions. TJsneas and other conspicuous forms, including Roc- 
cella tinctoria , on account of its coloring properties, seem 
to have been the lichens thus early described. A few ob- 
servers also studied lichens somewhat during the first cen- 
tury of the Christian era; but the dark ages soon inter- 
vened, and for several centuries, lichenology was, like 
other sciences, wholly neglected. With the revival of the 
sixteenth and seventeenth centuries, a few of the more 
conspicuous lichens were again described. As already 
stated, it was not till 1694 that lichens were for the first 
time recognized as a distinct group of plants, and at this 
time less than a hundred species were known. Such was 
the condition of the science of lichenology when the first 
work was done in America. 
The men who did this early work were not specialists in 
lichenology, for specialists in so limited a sense were 
hardly known at this time. But toward the close of the 
eighteenth century, there appeared a number of botanists 
who began to study the lichens somewhat seriously. 
Though careful study of the old literature has given me 
but 221 pre-Linnean (1753) lichens, Acharius, the first great 
lichenist, in his “Methodus Lichenum,” just a half century 
later (1808) described approximately 500 lichens then 
known. Such were the conditions at the beginning of the 
second century of American lichenology, and it may be 
added that the prevailing ideas regarding the apothecia, 
the soredia, the so-called spermagonia, the spermatia and 
the spores were crude and in general erroneous.' It is true 
that Acharius studied the spores as well as he could with 
the crude magnifiers of his day, and figured many apothe- 
cia, but even in his “Lichenographia Universalis” of 1810, 
his attempts at figures of spores are few and very unsatis- 
factory. 
