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1901] CURRENT LITERATURE 149 
Reproduction. The treatment of enzymes, which have become so important 
a consideration within the last few years, is comparatively full, both in the 
chapter on the composition of the plant and in that on nutrition, and will be 
especially useful. 
ollowing the chapters on processes within the plant, the last chapter in 
the book gives a very excellent exposition of the subject of vegetative propa- 
gation throughout the plant kingdom. Sexual reproduction is not treated. 
At the end is a valuable appendix containing tables of physical constants, 
such as the expansion of air at different temperatures from 0° to 35°, the 
density of oxygen and of carbon dioxid, the absorption of these gases by 
water, etc. It will be a great aid, in experiments where calculation is neces- 
sary, to have these tables in a convenient form for reference. 
Regarding the style, we wish it might have been clearer in places; there 
will surely arise difficulties of interpretation now and then. ‘The only impor- 
tant point of theory wherein the author may find others in disagreement with 
him is that which expresses itself here and there in the idea of some purpose 
underlying the whole field of plant phenomena. For instance, it is stated 
that there exist “reactions to shock . . . . which the most thorough investiga- 
tion has failed to invest with a purpose. New relations of the plant may be 
discovered, however, which will interpret these reactions.” 
The book is fully illustrated throughout, including many figures of appa- 
ratus. References to the most important recent publications on the different 
topics are given as footnotes, and both treatment and references are surpris- 
ingly up to date, articles being cited which appeared only a few months ago. 
The index is complete, and includes footnotes as well as text. The arrange- 
ment of the subject-matter is thoroughly scientific, which fact, together with 
its general completeness and reliability, should give the book a broad and 
constant use in laboratories where the subject is taught. 
Professor Ganong’s new book does not attempt to present any general dis- 
cussion of the subject, but is designed, as its title denotes, for laboratory use 
only. It is divided into two parts, the first being on methods of study and 
necessary equipment, while the second comprises the true outline of the 
course. Part I is written largely for the teacher, and every teacher of labor- 
atory science (whether it be physiology or not) will do well to read it. The 
first two sections of this part are especially noteworthy for their fund of ped- 
agogical ideas, which, it seems to us, are almost all philosophically and 
practically sound. The third and fourth sections deal with laboratory, 
greenhouse, and materials for the course. Section 5 gives practical direc- 
tions for a great number of laboratory manipulations, some of which often 
are a source of considerable trouble to the inexperienced. This will surely 
prove a very valuable part of the book. 
Part II, the outline of the course itself, consists of two divisions. Division 
