606 THE AMERICAN NATURALIST.  [Vor. XXXIV. 
in the determination of species to enable them to make ready use of 
such works as Gray's Manual and Britton and Brown's Flora. No 
help in learning how to analyze is here afforded, although the student 
is expected to determine during the course a considerable number of 
plants. To call the book “An Introduction to the Study of Botany " 
would seem to be, therefore, somewhat misleading. 
The prominence given to physiological matters leaves opportunity 
for but scant consideration of the form and structure of parts — 
scarcely enough, it would seem, for a full understanding of the text, 
except on the supposition that the student is receiving or has re- 
ceived supplementary instruction. Some of the morphological state- 
ments call for correction. Thus we find fruit defined as **the seed 
and all parts of the ovary adhering to it" (p. 155) — a strangely in- 
adequate definition, which is contradicted by the statement (on 
p. 176) that the “fruit of the apple is composed of portions derived 
from all the organs of the flower." It seems strange, also, to find 
such an unqualified statement of this old notion of the apple's mor- 
phology, in view of the simpler modern theory now generally adopted. 
As regards physiological matters the treatment leaves but little to 
be desired. One statement, however, would seem to require modifi- 
cation, namely, where it is said (on p. 45) that the spongy layer 
enveloping the roots of air plants will *gather water from the air 
when it is humid and damp." The careful experiments to test this 
matter by R. G. Leavitt, detailed in Rhodora for February and 
March, 1900, make it appear highly improbable that aérial roots 
ever have this power of absorbing watery vapor which has been 
frequently ascribed to them on meager evidence. 
In spite of its defects, which are not likely to prove of much con- 
sequence where there is a good teacher, the book is sure to rank 
well among recent helps to the study of plants as living things. 
F. L. S. 
Prantl’s Lehrbuch.  — The new edition of Prantl’s excellent 
text-book of botany follows essentially the same lines as the last 
edition, the chief modifications consisting of a general expansion 
which amounts to about fifty pages. Numerous changes and addi- 
tions in the matter of illustration have resulted in an increase of 
twenty-seven cuts. Several of these new cuts illustrate the micro- 
1 Prantl. Lehrbuch der Botanik, herausgegeben und neugearbeitet von Dr. 
Ferdinand Pax. Elfte, verbesserte und vermehrte Auflage. Leipzig, Engelmann, 
1900. 456 Pp., 414 figs. 
