748 
SUMMARY OP CURRENT RESEARCHES RELATING TO 
Fig. 96. 
per second or 1 litre per minute. Tlie tubes, which are made of tin or are 
tin-lined, are 3-6 mm. thick, with a bore of 1-4 mm. in diameter. To 
the filter there are fifteen turns up and down, each of them 2 cm. long. 
The filter may be used either extended as in 
fig. 94 or in the more compact form seen in 
fig. 95. 
Infection Needle.* — Mr. J. C. Bay de- 
scribes a needle used by him in the study of 
the lower cryptogams. The needle itself, 
made of brass or copper wire, passes through 
the centre of a metal disc /, and its lower 
part is surrounded by a glass tube g (fig. 96). 
The disc can move between two stoppers b 
and d. The upper end of the needle is bent 
round to form a grip a, while just below this 
is the spring c, the other end of which is 
attached to the glass tube g. Inside the 
tube is a cotton stopper e. When used, the 
upper part of the glass tube is charged with 
cotton, and this outside wrapper should be 
of the same size as the opening of the flasks, 
so that when the plug of the flask is removed 
for inoculation, the needle case exactly fills 
the neck. Fig. A shows the needle guarded, 
fig. B when pressed down for removing a 
sample from a culture. 
Setting Cultivations on Solid Media.f — 
Dr. P. Miquel fixes all kinds of cultivations 
by exposing them to the vapour of trioxy- 
methylen. In the dry condition this sub- 
stance gives off but little methylic aldehyde, 
to which its fixative property is due. It 
must therefore be moistened with water, or 
better, dissolved in a saturated solution of 
calcium chloride. It is only necessary to put 
the substance and the cultures under a bell- 
jar for twenty-four hours to about three days. 
The media are quite unaffected, the growths 
are all killed, and it is only necessary to 
hermetically seal up the culture vessel to 
prevent evaporation. The appearance of the 
cultures is unaltered as a rule, though oc- 
casionally chromogenic bacteria and some 
moulds lose a little colour. 
Parasitic Cell-inclusions and their Cultivation. :£ — Dr. 0. Busse 
has successfully inoculated cell-inclusions on animals, in which they 
have multiplied ; has obtained pure cultivations on various nutrient 
* Amer. Mon. Micr. Journ., xv. (1894) pp. 44-5 (2 figs), 
t Ann. de Micrographie, vi. (1894) pp. 422-3. 
j Centralbl. f. Bakteriol. u. Parasitenk., xvi. (1894) pp. 175-80 (4 figs.). 
