670 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
outset a slight diminution of the Bacteria, they soon grew well 
enough. 
Other two sets of experiments were made with 10 per cent, sugar 
and 10 per cent, pepton, each mixed with 10 volumes of blood. Both of 
these series as compared with a control series without sugar, showed that 
the addition made practically no difference. 
Hence it is obvious that neither the concentration of the medium 
nor the too sudden transition of the Bacteria to an unaccustomed medium 
makes any difference to the result. 
(2) Preparing- Objects. 
Method of Preparing Mucous Gland of Prosobranch Molluscs.* — 
M. F. Bernard found difficulty in obtaining reagents which were not 
either unable to coagulate the mucus or which were not too energetic, 
and so disformed the cells. He found, however, three mixtures which 
acted well, part of the gland being removed from the mantle as rapidly 
as possible. These were strongly acidulated picro-sulphuric acid; 
chloride of ruthenium of such strength that the solution is a clear red 
colour ; this was the best of the reagents employed, but unfortunately 
the author was not able to get as much of it as he wished ; it greatly aids 
dissociation with needles. The third mixture was made of 200 grammes 
of distilled water, 10 of alcohol at 90 per cent., 5 of glycerin, and 10 of 
acetic acid ; this solution facilitates the staining of the elements with 
methylen-blue. Fragments thus fixed were teased in 38 per cent, 
alcohol, osmic acid at 1/10,000, or the acid mixture just mentioned. The 
last gave particularly good results with animals from Naples which had 
been already fixed by alcohol or various other reagents. 
Mounting Insect Eggs to study the Embryo.|— Mr. E. A. Hill de- 
scribes a method devised by himself, which he has used for two or three 
years past, in collecting and preparing the eggs of Lepidoptera for the 
microscopic examination of the embryo in its various stages of deve- 
lopment. 
In summer evenings, when working with the Microscope, the window 
being open, as is usually the case, moths frequently fly in attracted by 
the light ; and when pursuing this line of investigation Mr. Hill has on 
hand a number of pasteboard pill-boxes (size is not important, but some 
which happened to be at hand were about 1 in. deep, and 3/4 in. in dia- 
meter). The moths are easily captured, after which each is placed in a 
separate box, with a reference letter on the cover. The next morning a 
number will usually be found to have laid eggs. These eggs are divided 
into as many equal parts as he anticipates there are days in the period 
of incubation, placing each portion in a separate homoeopathic phial, the 
phials being about 1 in. high. The corks are marked with the reference 
letter entered in the record book, and, in addition, the phials are num- 
bered consecutively from 1 upwards. The corks are inserted lightly, so 
as to allow air to enter the phials. Phial No. 1 is then filled at once 
with carbolic acid, filling No. 2 on the second morning, No. 3 on the 
third morning, and on the last day filling the phial containing the newly 
* Ann. Sci. Nat., ix. (1890) pp. 305-6. 
t The Microscope, x. (1890) pp. 208-10. 
