464 BOTANICAL GAZETTE [JUNE 
the flora of eastern North America in connection with the Tertiary 
flora of Spitzbergen.” He was deeply interested in Dr. WIELAND’S 
work on the fossil Cycads, for which he had a great regard, although 
he did not approve of the application of the term Cycad to the fossil 
stems which he maintained differed too widely in the fertile shoots 
from the Cycadales to be placed in that group. NatTHoRST’s own works 
on the Cycadophyta (a class designation which he instituted) not only 
added greatly to our knowledge of the extinct types, but stimulated 
other workers in the same field. 
It is impossible in a short article to give an adequate idea of 
NAtTHoRS?T’s contributions to paleobotany. Among his better known 
researches are those on Arctic floras from Devonian to Tertiary, his 
series of Paleobotanische Mitteilungen in which many new types, notably 
Devonian and Rhaetic genera, are described, his thorough study of the 
Rhaetic and Liassic floras of Scania, the series of papers on supposed 
fossil algae which were: revolutionary and had a far reaching and 
salutary influence, his work on the distribution of Arctic plants during 
the Glacial period inspired by his first-hand knowledge of recent Arctic 
plants, his numerous contributions to our knowledge of Mesozoic floras 
in widely separated parts of the world, from Graham Land and the 
Falkland Islands to the new Liberian Islands, and his stimulating 
papers on British fossil plants. Although he did not concern himself 
with the investigation of petrifactions, his skilful use of improved methods 
which he invented for examining the mummified cuticles of impressions 
led to astonishing results. 
Natuorst had the true scientific spirit. His work was based on a 
firm foundation of accurate and wide knowledge of botany and geology; 
he recognized the limitations of his material and never ventured to deal 
with matters on poops he was not competent to speak with the authority 
of a specialist. In 1895 he wrote in one of a long succession of most 
helpful letters, ret chief rule in dealing with fossil plants is that one 
ought to say precisely as much as the material allows, neither more nor 
less. This is the ideal, but one cannot help sometimes saying a little 
too much in consequence of what one besides (that is, beyond the 
available evidence) does believe!’ He strongly deprecated the over- 
confidence of some paleobotanists and their departure from a whole- 
some skepticism. In 1919 he wrote in a letter, ““The longer I live, the 
more my skepticismus is developed, although my projected great work 
on Skepticism in paleobotany in twelve volumes will probably never 
appear!” He took a delight in helping others with kindly encourage 
