REcENT FERN LITERATURE i Bes 
eastern America, unknown in Europe but appearing 
in eastern Asia; the plant known only from the coastal 
region of the eastern United States and portions of 
the Mississippi basin, are already old friends to stu- 
dents of plant geography. Moreover, the two eastern 
species were described long ago and have been very 
generally considered by European botanists and fern- 
srowers as distinct from the European lady-fern; only 
in their own country have they been without honor. 
All three species will have their difficulties for the 
beginner, since the really crucial characters by which 
they are distinguished are microscopic; but there are 
fnough obvious differences in rootstock, outline of 
frond and length of stipe to make them recognizable, 
after a little study, to the amateur, unarmed with a 
‘ompound microscope. All three vary considerably 
and along essentially parallel lines in the shape and 
cutting of pinnae and pinnules; such differences cannot 
be depended upon in naming specimens. 
na similar study of Botrychium virginianum, Pro- 
fessor Butters distinguishes seven geographic varieties 
of that species, characterized chiefly by the size, color 
and manner of dehiscence of the sporangia. 
“Fern Notes,” by Mr. O. A. Farwell,’ presents, rs 
author tells us, the results of several years’ researches 
™ field, herbarium and library. They will he of the 
‘More interest and stimulus to fern students, because 
Mr. Farwell has his own point of view aia sik te kis 
use of names and in classification, is inclined to depart 
from, the usage familiar to us in current man uals. Hor 
| ean he reduces Lycopodium sabinaefolium, L. 
Setachypum, L. alpinum and L. sitchense all to varieties 
fich. Acad. Sci. 18: 
1 
> Farwell, Oliver Atkins. Fern Notes. Ann. Rep. 
$94. fig. 13. 1917, 
