120 BOTANICAL GAZETTE | AUGUST 
In this connection attention should be called to the fact that in the cases 
cited by the author the rainfall of August and September is fully up to the 
average for the sixteen years quoted, and that these are the critical months 
which determine what the yield of the potato crop shall be; hence it is pos- 
sible that the results obtained were due quite as much to the rainfall of the 
two months cited as to the frequent inter-tillage which the crop received, and 
which is looked upon as the chief factor in securing the large yield. These 
suggestions are made not in the spirit of adverse criticism, but simply to call 
attention to the manner in which this and all similar books should be read.— 
F. H. KING. 
The Illustrated Flora.? 
THAT the second volume of this important work should follow after the 
first at an interval of less than a year is a matter of surprise to many familiar 
with the usual delays in the preparation of such extensive works. To those 
who know Dr. Britton, however, this evidence of rapid and continuous work 
is no great surprise. The families treated in the present volume are of more 
general interest than those presented in the first, and give a better exemplifi- 
cation of the principles controlling the work. These principles need no fur- 
ther mention than that made in our review of the first volume. The sequence 
of families, that of Engler, certainly commends itself still more as a rational 
one when applied to our own familiar groups, and there should be no hesita- 
tion in using it. The general principles of the nomenclature adopted have 
already received the sanction of the GAZETTE. From our standpoint, how- 
ever, the most serious changes in the nomenclature of the book arise not from 
the application of certain rules of nomenclature, but from the extreme views 
as to generic limitations. We are wiiling to grant that we have been entirely 
too conservative in holding together very distinct groups of species under a 
single genus, and this movement toward the breaking up of our polymorphic 
genera commends itself to our judgment. Such breaking up, however, may 
be carried to such an extreme that a genus will entrench too closely upon our 
conception of a species. We still believe that there is room for such a taxo- 
nomic group as a subgenus. This is so largely a matter of individual judg- 
ment, however, and affects so little the usefulness of the book under consid- 
eration, that it needs no further mention. 
So h has been published recently upon our northeastern flora in a 
scattered way, that probably the greatest value of the book to the professional 
taxonomist is to have all this new material organized in systematic fashion, 
BRITTON, NATHANIEL Lorp, and Brown, Hon. Appison. An. illustrated 
flora of the northern United States, Canada, and the British possessions, etc. Volume 
Il. Pp. 643. Portulacacexe to Menyanthaceze. New York: Charles Scribner’s Sons, 
1897. $3.00. 
Petra ot see Rares ee 
