312 BOTANICAL GAZETTE [APRIL 
-made room for more interesting and important material. Particular attention 
is given to economic plants, especially those which have medicinal properties. 
The number of illustrations has been increased from 686 to 741. Many 
of the old figures have been replaced by new ones, and the colored figures» 
which have always been a feature of the book, have been much improved by 
recent methods. Both authors and publishers deserve commendation for the 
frequent editions which have kept this work so thoroughly up to date.—C. J. 
CHAMBERLAIN. 
Alpine vegetation. 
ONE OF THE most valuable of tasks today is the compilation and syste- 
matization of scattered material. Such a labor has been performed by Marie 
Jerosch+ in connection with the alpine vegetation of Switzerland. No claim 
to original work is put forth, although the critical study of 250 titles and the 
molding of discordant data into a harmonious whole are at least of equal 
value with most original investigations. 
The work is essentially floristic rather than ecological. The first chapter 
deals with fundamental principles and motives, such as the origin of species, 
plant migrations, and polytopic appearance of species, The author is 
favorably inclined to all of the current evolutionary theories, and gives 
especial attention to Wettstein’s seasonal dimorphism, and to mutation; the 
claim is made that Heer held a view essentially equivalent to mutation. 
The polytopic theory of Briquet is treated fully, but not very favorably. The 
second chapter considers the alpine and arctic climates from a comparative 
standpoint. The third and fourth chapters have to do with the Tertiary and 
Pleistocene history of the alpine regions. Then follows an aceount of post- 
glacial changes, leading to a detailed consideration of the elements of the 
present alpine flora, together with their age and origin. Jerosch holds that an 
interglacial xerothermic ‘or steppe period has been proved by the facts of 
plant geography, paleontology, and geology; there is more doubt as toa 
similar postglacial period. 
There is no better illustration than that afforded by this book of the 
possibilities in floristic study. The glacial and postglacial floras of Switzer- 
land and Scandinavia with all their vicissitudes are known almost as accurately 
as the floras actually in existence today. The fact that almost nothing is 
known of the glacial and early postglacial vegetation of America ought to 
stimulate many to study jn this important and productive field.—H. C. 
COwWLEs. 
Ecology of the Lena valley. 
CAJANDER has given an excellent account of the vegetation of the allu- 
vium of the lower Lena’, in which particular attention is paid to the genetic 
*JeRoscH, MARIE, Geschichte und Kerknuft der schweizerischen Alpenfiora, 
Leipzig: Wilhelm Engelmann, 1903. 78, 
SCAJANDER, A. K., Die Alluvionen des unteren Lena-Thales. Helsingfors. 
1903. 
