172 Rhodora [SEPTEMBER 
permanent foundations of science, and of such, for its region and 
problem, the present work is a treasury. 
In this as in others of his writings Professor Nichols shows generous 
appreciation of earlier ecological investigation, which he does not 
insist upon judging by present day standards. He corrects mistakes 
on the merits of the evidence, and is wholly above that form of weak- 
ness which consists in using the errors of others as a foil to show forth 
by implication one’s own cleverness. 
Any criticism of the paper would center in two minor points. The 
reproduction of the illustrations is in many cases not wholly adequate 
to the obvious value of the originals. This is a common fault in our 
ecological publications, and we should insist upon better results. 
. Again, the system of ecological nomenclature, while perfectly logical, ` 
is, to the reviewer at least, lacking in clear definition and therefore 
somewhat confusing in use. An ideal nomenclature would measure 
up in differentiation to the distinctness of the groups themselves.— 
W. F. Ganong, Smith College. 
A FLORA OF NORTHEASTERN PENNSYLVANIA.— A reliable local 
flora is, in the present stage.of knowledge of the distribution of plants 
in North America, always most welcome. Very many areas are as 
yet not blessed with such detailed publications and every addition to 
the list of carefully prepared reference works is to be commended. 
Recently, we have received a copy of the “Flora of Northeastern 
Pennsylvania” by Alfred Twining, published by the Everhart Mu- 
seum of Natural History, Science and Art of Scranton, Pennsylvania. 
The work bears such evidence of painstaking care in securing accurate 
verification of the most technical groups of plants that a copy should 
be in the hands of everyone who is specially interested in working out 
detailed ranges. The region covered is only 50 to 100 miles west of 
southwestern New England and the botanists, particularly of Con- 
necticut and western Massachusetts, will be specially interested in 
it. —M. L. F. 
Vol. 21, no. 248, including pages 133 to 148, was issued 7 August, 1919. 
