256 BOTANICAL GAZETTE [ APRIL 
ances should be possible. No doubt when the stimulus of a 
wide use in teaching shall direct the proper combination of 
physiological knowledge and inventive skill more extensively in 
this direction, astonishingly simple ways of demonstrating impor- 
tant facts and principles will be found. Much has already been 
done along this line, but every teacher knows that many of the 
apparently simple experiments of the books are not actually 
practicable, nor do they always cover the more important topics. 
Just here, indeed, lies the kernel of the whole matter ; it is not 
only practicable experiments that are wanted, but experiments 
upon the most fundamental topics, absorption, transfer, transpi- 
ration, photosynthesis, respiration, growth, irritability. One good 
experiment upon such themes is worth many upon minor ones. 
No doubt the subject will ultimately work itself out for ele: 
mentary classes in much the same way that it has already done if 
physics, namely, in the form of a standard series of a dozen of 
fifteen experiments on the leading topics, the apparatus for which 
will be purchasable at a fair cost from supply companies. 
The appliances here to be described have been develope 
the author’s courses in Smith College. Every piece has beet 
many times tried and is known to be practicable. 
d in 
1. A temperature stage. 
variations of 
e in itself, is 
ponse to 
The response of protoplasmic movement to 
temperature, even if not a topic of much importance 
worth studying as a fine example of quantitative Te we 
external influences, and especially as an introduction to ee 
statistical method of studying physiological phenqne des. 
not, of course, for beginners, but for those of nid 
For this work a temperature stage is necessary, prefera y 
for each student ; but those on the market cost from 57 
cost is shown in fir. r. It is of sheet copper, 0? Hed ovet 
: : : ro 
an inch thick, of t f a microscope stage, 
of the breadth o Pp ae ometet 
as shown by the figure to make a chamber for 
ight. For 
and another for a three-inch slide, with holes for the lig 
