1887.] MICROSCOPICAL JOURNAL. 133 
ney K, when the heat will escape, by the branch chimney F. The temper- 
ature of the bath will now fall slightly, and the mercury with it away from 
-B, thus breaking the circuit, and demagnetizing the electro- magnet, which 
all cease to aermee the lever, and so allow the valve to fall, ~ fh its own 
weight, closing the opening into the branch chimney, and allowing the hot 
air to again ascend through K, and reheat the water bath. 
This regulating action will continue as long as any oil remains in the 
lamp, which should therefore have a large reservoir, and the flame be turned 
only high enough to keep the bath slightly above the femperature desired. 
The water bath which I have is 7 inches long, 6 inches wide, and 5 inches 
deep, and has openings for two imbedding aches the regulating, and stand- 
ard thermometer. Into it at one end is built an oven, with six shelves, 
which will take 24 slides for drying. The whole, including chimneys and 
‘hot-air chamber, is of copper, and was made by a tinsmith, after my direc- 
tions, at a cost of but five dollars. With this apparatus many processes, 
such as Weigert’s hematoxylin staining of the nervous system, which without a 
constant temperature, of long continued duration, are impossible of perform- 
ance, are made easy, and any one, who has had the bother of watching a 
bath, while imbedding in paraffine, will appreciate the gain arising from an 
apparatus which ii run all night, and have the Poses in good candies 
for imbedding in the morning, to say nothing of the many pthen uses besides 
staining and imbedding, to aatieeh it can be put. 
APRIL 30, 1887. 
EDITORIAL. 
Summer work.—Those who are interested in biological studies may find 
the summer time, when they are tempted to relax a little, the very best time 
for work in the whole year. Histological studies on hardened material may, 
to be sure, be carried on as well in the winter or, perhaps, even better; but 
after all histological studies on hardened material should always be made after 
structures or whole animals have been studied alive; and perhaps the most 
important and interesting studies in all the range of biological works are those 
which can be pursued only in the summer time. Without desiring to draw 
any invidious comparisons, or to pronounce against any one pet form of work 
as inferior to any other, we must all recognize that some lines of study are 
more important than others from the biologist’s standpoint. Since the chief 
interest of the biologist centres around the origin and mode of growth of 
living organisms as problems to be more fully worked out, studies upon the 
life history of all forms engross the chief attention. We cannot infer, from 
close similarity in adult anatomy, a close resemblance in embryonic history ; 
for, in many cases closely similar adults come through very dissimilar and 
devious roads, as the cray-fish and his salt-water cousin, the lobster, and their 
cousin, the shrimp (Peneus). So the story for each species needs to be fully 
Efudied. 
There is, then, a whole field of study closed to the biologist who studies 
only in the winter time and folds his hands during the summer season—a 
field which will furnish him some of his most interesting subjects of study. 
Who lives on or near the salt water has, in this matter, an immense advan- 
tage. A few minutes’ use of the dip-net at high tide will give him an 
immense assortment of adult and embryonic forms from which to select those 
he wishes. He can find larve of crustacea and, isolating them in little 
aquaria—where he must be careful to make frequent changes of water, for 
