152 
8UMMARY OF CURRENT RESEARCHES RELATING TO 
sheet of paper. The author employs them in two sizes — one 16 cm. 
long by 15 mm. in diameter, the other 18 cm. by 25 mm. ; the former for 
stroke and puncture cultivations, and for small quantities of fluid media ; 
the larger size for potato cultivations, for large quantities of solid or 
fluid media, aud for purifying agar. 
For facility of sterilizing in dry or moist heat, for cultivations in 
any kind of media and with any kind of gaseous environment, the author 
states that this simple device gives very encouraging results, and 
obviates at the same time many of the inconveniences of cotton-wool. 
Apparatus for filtering Gelatin.* — Dr. Schill points out that 
gelatin may be filtered much more rapidly than by the ordinary filter by 
means of a vessel the bottom of which is perforated by a number of 
holes — so many more filters, in fact. The bottom of the vessel is of 
course covered with filter-paper. 
The simplest way to make the apparatus is to knock off the top 
of a preserve-tin or jam-pot, and make holes in the bottom with an 
awl or gimlet. The holes are made inwards. The bottom is then 
covered with filter-paper, the edge of which is made to lap up along the 
side of the vessel. The filter-paper is supported by a double layer of 
book-muslin, from which all grease has been carefully removed, and 
this is fixed round the filter by means of a rubber band. 
For hastening the process of filtration, atmospheric pressure may be 
made use of. In this case the filter-vessel must have a top with a hole 
fitted with a caoutchouc stopper perforated for the passage of a glass 
tube. To the outside end of the tube is applied a funnel, while the 
lower end reaches very nearly to the bottom of the filter. Consequently 
as soon as a thin layer of gelatin forms at the bottom of the filter, the 
air above is compressed, and this accelerates the flow of the fluid. In 
other respects the apparatus is the same as the previous one. The 
filter apparatus may be made of wood or tin, but best, of course, of 
glass or porcelain. 
Graduated Capillary Pipette for measuring very small quantities 
of fluid.j" — Dr. G. Gabritschewsky has devised a pipette by which it is 
possible to remove a deposit from 0 • 001-0 '1 ccm. or any intermediate 
quantity of fluid. The instrument is made on the same principle as 
that used in the enumeration of red corpuscles, and fitted at the end 
with a rubber tube clipped by a screw-clamp. The pipette, the exact 
form of which is given in an accompanying illustration, is chiefly in- 
tended for estimating the number of bacteria in a fluid. The instrument 
is to be cleaned after each time of using with dry heat, alcohol, ether, 
and water. 
(2) Preparing- Objects. 
Study of Development of Cephalopods.j — Mr. S. Watase separated 
the blastoderm from ova, which he had artificially fertilized and kept 
alive, by killing the egg at any given stage of division by a mixture of 
sea-water, acetic and osmic acids, as recommended by the Hertwigs for 
their macerating fluid. The osmic acid may be reduced in quantity or 
* Centrulbl. f. Baktcriol. u. Parasitenk., x. (1891) pp. 659-GO (2 figs.), 
t Tom. cit., pp. 248-9 (1 fig.), 
t Journal of Morphology, iv. (1S91) pp. 219 & 50. 
