CURRENT LITERATURE. 
BOOK REVIEWS. 
Handbook of systematic botany. 
THE first volume has appeared of a handbook on systematic botany by 
Dr. Richard R. v. Wettstein,' of the University of Vienna. We do not often 
have texts that confine themselves so closely and accurately to the subject as 
does this very excellent outline of classification. Its aim is to give a general 
view of the plant kingdom with especial reference to the evolution of phylo- 
genetic lines. Prefacing the special parts, which deal specifically with the 
groups of plants, there is a general treatment of a number of interesting 
topics. There is first an historical account of the development of systematic 
botany, which one wishes were longer. This is followed by discussions of the 
conditions which lead to the development of lines (phyla) of ascent and the 
sort of evidence of value in the determination of the same. There is an 
excellent account of the methods of systematic botany and the data of most 
value in studies on classification. Admirable illustrations are presented of 
analogous and homologous organs, rudimentary structures and juvenile 
forms. Finally the author considers the origin of new forms on the supposi- 
tion of phylogenetic evolution, or in other words the principles of Darwinism. 
This is in the maina simple account of evolutionary factors, and is particularly 
d 
tance of the so-called ecological factors in the definition and adjustment of 
species, 
Following the short general part, which is only forty-four pages long, 
comes the special part that will deal entirely with the various groups. 
The present volume ends with the thallophytes, but we are promised the 
completion of the subject next year. The author divides the plant kingdom 
into seven branches, as follows: 1) Myxophyta, 2) Schizophyta, 3) sushi 
phyta, 4) Euthallophyta, 5) Phaeophyta, 6) Rhodophyta, and 7) Cormo- 
phyta. The success of a division into great groups depends saree Se upon 
the balance maintained, and this one has some peculiar disadvantages in its 
lack of symmetry. It will hardly be questioned that branches I, 2, 3, 5, and 
6 are well differentiated phyla or closely related groups of phyla. But this 
simplicity is all out of proportion to the complex conditions presented in the 
* WETTSTEIN, RICHARD V.: Handbuch der sg agi Botanik. Vol. 1. 8vo. 
pp, vi+201. figs. 762. Leipzig: Franz Deuticke. 
Igor} 61 
