ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
5G9 
other and separated by a distance of abont 4 mm. The rods are about 
5 mm. in diameter. They are raised about 2 mm. from the bottom of 
the dish and fastened only at the extremities, thus permitting of a free 
circulation of the liquids. The cover-glasses are placed on edge between 
the rods, against which they rest (fig. 86). A reservoir of this size will 
hold, without crowding, thirty preparations on 3/4-in. covers. It is 
desirable to have a reservoir for each of the liquids used. The cheap- 
ness with which they can be made does not render this objectionable. 
The construction consists in procuring the desired number of £ double 
dishes,’ a few feet of glass rod, and an ounce or two of liquid glass 
(silicate of soda), or a few feet of fine copper wire. The glass rod is 
easily broken, by the aid of a file, into pieces of the required length, 
which are fastened in their respective places by means of a few drops of 
the liquid glass. In order to raise them from the bottom of the dish a 
ring composed of the liquid glass is built up around the edge, upon 
which the ends of the rods can rest and upon which they are fastened. 
As the silicate of soda is soluble in water and dilute alcohol, it is neces- 
sary to dehydrate it after the rods are fixed, so as to render it insoluble. 
This can be done by heating the reservoir in an oven or hot-air chamber 
at a temperature of about 98° C. If the reservoir is to be used only for 
turpentine, absolute alcohol, &c., the drying of the silicate of soda in 
the air is sufficient. 
Instead of fastening the rods in the dish they can be bound together 
by means of fine wire, preferably copper, in the form of mats, which 
answer every purpose, and which can be removed at will if the dish is 
desired for other purposes. This is easily accomplished by running 
the wire around the ends of the rods after they have been cut the desired 
lengths. A shoulder-like projection can be procured on the ends of the 
rods by heating them until soft and pressing them against a firm surface. 
These prevent the wire from slipping off, and also raise the rods from 
the bottom of the dish (fig. 87). 
With a full set of these reservoirs thirty cover-glasses can be carried 
from the first to the last liquid quite as quickly as a single preparation, 
for the time necessarily required for the action of the various reagents 
on a single specimen can be profitably employed in transferring other 
preparations. The cover-glasses can be handled very quickly, neatly, 
and with perfect safety with a pair of fine forceps.” 
(6) Miscellaneous. 
Demonstration of Heliotropism.* — Herr F. Noll has constructed a 
heliotropic chamber for the growth of Pilobolus crystallinus . Light is 
admitted to the chamber only through a round pane of glass on one side. 
When the fungus was grown on a suitable substratum within the 
chamber, it was found that the sporanges had all discharged their 
spores on to the pane of glass, many of them striking it almost in the 
centre. 
Demonstrating the Pigment of the Floridese.t — Herr F. Noll 
describes a contrivance for exhibiting in the lecture-room the mode in 
which the green colour of the chlorophyll is completely masked by the 
* Flora, lxxvii. (1893) pp. 32-7 (1 fig.). f Tom. cit., pp. 27-31. 
