804 THE AMERICAN NATURALIST. {VoL XXXII. 
with the last-mentioned works to have acquired the habit of opening 
them readily to any desired family or genus of plants, he will also be 
annoyed because the sequence of families in the present work is not- 
at all the same. These differences come from an effort to follow the 
sequence of groups of the great German treatise of Engler and 
Prantl, on the families of plants, and the nomenclature rules of the 
Botanical Club of the American Association for the Advancement of 
Science, as exemplified in the: check list of the plants of eastern 
North America, published by its committee in 1893-94. Less 
objection will be made to the first than to the second of these 
changes from American custom, and, notwithstanding the difficulties 
of the undertaking, the authors of the book have been reasonably 
consistent in carrying out their ideas, so that it is going to prove an 
important factor in fixing the names preferred by the Neo-American 
school upon our plants; whether wisely or unwisely, it may be left 
for the future to show. T. 
Detmer and Moor’s Physiology.’ — The guide to practical labora- 
tory work in a comparatively new field never comes amiss, and 
although several such guides in vegetable physiology are now in 
the hands of English-speaking teachers, this translation of Detmer’s 
well-known Praktikum is a very welcome addition to their shelves. 
Nature study is frequently spoken of as a means of training the 
power of observation, but it is useful even to a greater extent as an 
educational factor, because it is an experimental study if properly 
pursued. Experimentation is largely a matter of personal ingenuity, 
like mechanical invention. In any direction, its foundations are laid 
by a small number of specially gifted men. But just as soon as their 
methods are understood, they may be applied by hundreds of other 
students to the solving of problems that are everywhere awaiting 
solution. Every book which, like Detmer’s, outlines the general field 
of study and indicates the simplest apparatus and methods for 
attacking it, paves the way for the elaboration of refinements in the 
investigation of special subjects. 
The topics treated are : the physiology of nutrition, and the physi- 
ology of growth and movements resulting from irritability. For these 
1 Practical Plant Physiology. An introduction to original research for students 
and teachers of natural science, medicine, agriculture, and forestry. By Dr. W. 
Detmer. Translated from the second German edition by S. A. Moor. 8°, pp- X1x 
+ 555. 184 illustrations. London, Swan, Sonnenschein & Co. New York, The 
Macmillan Company. ; 
