66 BOTANICAL GAZETTE {yuLy 
amount of energy is actually set free during the metabolic process of Methanomonas 
methanicus. From this genus evolution progresses in four directions, toward the 
Protozoa, the Eumycetes, the Cyanophyceae, and toward the putrefying and 
pathogenic forms. The tree of descent thus outlined is ingenious, and species 
seem to fall into places of natural relationship. This, however, may only meat 
that generic distinctions are founded on seth catablichell biological properties, 
for it is probable that bacteriologists will hesitate to accept a primary division 
into orders on a basis of the distribution of flagella —Mary HEFFERAN. 
Botanical directory.—A third edition of Dérrter’s Adressbuch was issued 
some months ago.” It is needless to commend this useful volume to those wid 
know the earlier editions; but we do a real service to any who do not by directing 
their attention to the greatly improved third edition. The list of botanists with 
their addresses and specialties is of course the main feature; but very useful als 
are the lists of botanical periodicals and societies. 
If any fault is to be found with the directory it is because it includes too mouch 
rather than too little. For example, we would have spared gladly the 270 page 
of so-called “bibliography’’—really a trade catalogue; but perhaps the author, 
who is also the publisher, could not afford (financially) to leave it out. 
urther, there are too many names included. How to sift the real botanists 
from the tradesmen and notoriety seekers is a difficult problem; for some of our 
best-known but heedless botanists have not responded to the circulars of the 
editor, and many of the sham botanists have. Judging by the United States list 
the numbers might be reduced 50 per cent., for everybody knows that there are 
indispensable volume.—C. R. B. 
Mechanics of plants.—Those who desire a compact and authoritative state: 
ment of SCHWENDENER’S present views on the mechanics of plants, as set fo ind 
course of special lectures given regularly for advanced students in the ; 
semester at Berlin, will find them in a thin volume® recently published by im . 
7 Dorrter, J., Botaniker-Adressbuch. Sammlung von Namen und Adressen 
lebenden Botaniker aller Lander, der botanischen Garten und der die — plese 
den Instituten, Gessellschaften und periodischen Publikationen. Dritte neu beat rbeitéf 
und vermehrte Auflage. 8vo. pp. vilit+4s0. Wien: The author (III, * Barichgas® 
36). 1909. $3.35. : 
8 HOLTERMANN, CARL, SCHWENDENER’S Vorlesungen iiber mechanische Pot 
der Botanik, gehalten an der Universitat Berlin. 8vo. pp- vi+134. With a : 
SCHWENDENER and go figs. Leipzig: Wilhelm Englemann. 1909. M 3 
