Jf 
1014 The American Naturalist. [November, 
studied. The demonstrations—by the developmental chain from the 
lower to the highest plants—that the pollen plant is itself an inde- 
pendent plant, is instructive. 
Let us see what the method of presentation should be in the depart- 
ment of plant physiology. In its modern aspect, this is rather the 
newest field of botanical investigation. It is commonly supposed to 
be quite beyond the resources of an ordinary equipment, and is men- 
tally associated with regiments of flasks, brigades of induction-coils, 
and whole armies of expensive and delicate pieces of apparatus. 
Certainly all the resources of chemistry, physics, and mechanics may 
be brought to bear upon the science of botany, and the result is our 
present mechanical or physico-chemical theory of plant life. But, 
although one may conduct experiments of great delicacy, it is scarcely 
imperative, on that account, for the teacher trying to give an evenly 
balanced six fortnights of botany to present such experiments. The 
truth is, one may do, most of the physiological experiments without 
apparatus. Seedlings planted in little boxes which may be set on edge 
illustrate geotropic curvatures; others set in the window illustrate the 
heliotropic position. To etiolate a plant needs but an empty flower- 
pot turned over it. Tissue tensions are illustrated by slicing a radish 
or parsnip and soaking awhile in water. Tendrils may be stimulated 
to curvature, bladderworts and pitcher-plants may be grown for exami- 
nation, leaves may be covered with felt pads to illustrate the transitional 
movements of the chorophyl bodies within ; the phenomena of wilt- 
ing, artificial culture solutions, Gemenii, temperature changes 
in germinated seeds, and a hundred others are demonstrated without 
difficulty. 
For such a course there is no text-book. The teacher must give it 
by brief lectures, or better, by occasional dictations. Some such 
compilations as Dr. Goodale’s ‘ Physiological Botany,” or ‘‘ Vine’s 
tures on Plant Physiology,” may be used for reference. Pfeffer 
and Detmer are the best authors for those who read German, and 
Frank’s little books are admirable. By such a course, brief though it 
may be, the student will learn that there is not a position of a leaf, 
not a coil in the tendril, which has not its sufficient cause. Thus he 
will learn in proper fashion what is meant by scientific investigation. 
It may be urged, and not without reason, that such courses as have 
been briefly outlined are too extended for the time allotted them. 
Such is not the case, however, for such courses are practical, as is 
shown by their adoption in more than one college and academy in 
America. Students should not be persistently underrated. Even 




