FERNS, FOSSILS AND FUEL 
for one or two years in bryologic work, and afterwards 
aided him in various ways in carrying on his paleobotanic 
investigations in the United States. 
The microscopic work connected with the bryologic 
studies affected Lesquereux’s eyes; so he turned to paleo¬ 
botany, which, at that time, did not require the use of 
a microscope. 
His first work on fossil plants was published in 1854, 
and from that time until the date of his death in October, 
1889, he wrote innumerable monographs and other 
papers on the fossil plants of North America for the 
United States Geological Survey and for the state sur¬ 
veys, especially the geological survey of Pennsylvania. 
The serial publications of almost all state surveys which 
deal with coal and coal-age fossils contain contributions 
by him. His extensive collections are now largely in 
Princeton University, together with his library. Many 
of his specimens are also in the Smithsonian Institution 
at Washington and a few of them are in the paleobotanic 
collections of the University of Chicago. 
A similar service, but under less difficult circumstances, 
was rendered to the paleobotany of Canada by Sir 
William Dawson, the late principal of McGill University. 
The basis from which these two men started was the 
life-work of Adolphe Brongniart, who had first treated 
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