OLUME L NUMBER 6 
BOTANICAL GAZETTE 
DECEMBER 1910 
THE PTEROPSIDA’ 
EpwarRr C. JEFFREY 
(WITH PLATE XIII) 
Two years ago, I published a reply to the various criticisms 
, which had been made from time to time of the great group of 
vascular plants defined as Lycopsida. At that time a promise 
_ Was made that the attacks, neither few nor unimportant, leveled 
at the pendent and corresponding phylum Pteropsida, would 
likewise be met. In the interval my time has been very much 
taken up with investigations on the higher seed plants, and it has 
tofore been impossible to carry out the intention then expressed. 
The delay, however, is rather an advantage than otherwise, for 
has enabled the opposition to the conceptions connected with 
the Pteropsida to crystallize and clarify, which materially simpli- 
the task of criticism. Moreover, in the past two years we have 
Seen venerable but no longer useful morphological doctrines go by 
the board. Their disappearance is of importance in the present 
connection, because they have been haled into court in the present 
sion. 
The validity of the Pteropsida, as a natyral phylum, may 
apparently now be taken as settled, since the group as defined by 
the present writer has been adopted by a number of botanists, 
whose knowledge, at once profound and extensive, of living and 
extinct vascular plants makes their opinion of the greatest weight. 
ere appears accordingly to be no serious opposition at the 
Present time to the conception that all those Vasculares which are 
- * Contributions from the Phanerogamic Laboratories of Harvard University, 
30 
