148 BOTANICAL GAZETTE [ AUGUST 
Two new books on plant physiology.’ 
THE dearth of text-books on plant physiology seems about at an end. We 
record with pleasure the almost simultaneous publication of two books on 
this subject, one by Professor D. T. MacDougal, of the New York Botanical 
Garden, the other by Professor W. F. Ganong, of Smith College. It is sig- 
nificant that both these books are American. 
he first named volume comprises a very comprehensive, though necessa- 
sarily brief, account of the phenomena of plant physiology, together with 
explicit directions for laboratory experimentation. Discussion of principles 
and laboratory directions are so interwoven that the temptation for the stu- 
dent to work mechanically, without other end in view than to finish the 
experiment, must here be reduced toa minimum. For this reason the book 
may be found more useful on the laboratory table than in the reading room. 
The mere reader will often be disappointed by the absence of measurements, 
etc,, since it is intended that these shall be obtained in the laboratory. On 
the other hand, it will be well-nigh impossible for one to peruse any section 
without gaining a fair knowledge of the methods by which the principles 
there treated are established. 
After an introductory chapter on the nature and relations of an organism 
(in which many statements are unavoidably made which the student cannot 
understand until he has gone further) the author devotes seven chapters to 
the presentation of the subject of irritability. In each of these a group of 
external conditions and the influence of these upon the plant is taken up. 
These chapters are headed as follows: Relations of plants to mechanical 
forces, Influence of chemicals upon plants, Relation of plants to water, Rela- 
tion of plants to gravitation, Relation of plants to temperature, Relation of 
plants to electricity and other forms of energy (although there are no “other 
forms” mentioned here), and Relations of plants to light. The chapter on 
the influence of chemicals will be found especially valuable. The next 
chapter (1x) deals with the composition of the body, and consists of avery 
brief treatment of the different groups of compounds found in the plant, fol- 
lowed by methods for their extraction, separation, and identification. This 
discussion is so brief that the reader may be led into error by generalizations ; 
and students will need to be cautioned that the qualifying phrases in the 
chapter are very important. 
Following this are five chapters on the processes going on within the liv- 
ing plant. These are entitled: Exchange and movements of fluids, Nutri- 
tive metabolism, Respiration, Fermentation and digestion, Growth, and 
3MacDoueat, D, T.: Practical text-book of plant physiology. 8v0- PP- xiv + 
gs. 159. New York: Longmans, Green & Co., 1901. 
GANONG, W.F.: A laboratory course in plant physiology, especially as 
ecology. 8vo. pp. vi+ 147. figs. 35. New York: Henry Holt & Co., 1901. 
352. 
a basis for 
