118 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
L emigre, G. — Un appareil simplifie pour la numeration des bacteries. (A sim- 
plified Apparatus for Counting Bacteria.) 
Journ. Sci. Med. Lille , 1894, pp. 169-75. 
Unna, P. G. — Natiirliche Reinkulturen der Oberhautpilze. (Natural Pure Cultures 
of Epidermal Fungi.) Mtsh.f. Pralit. Dermatol., 1894, pp. 257-67. 
C2) Preparing- Objects. 
Centrosomata.* — Dr. M. Heidenhain observed the following technique 
in his researches on centrosomata. For preserving he used especially 
sublimate and Flemming’s acid mixture ; for staining, Bordeaux R, 
Biondi’s solution, iron-hsematoxylin, triacid-solutions of Ehrlich. The 
best nuclear staining he has yet seen was got with thionin (Ehrlich- 
Hoyer). For differential staining he used, in the first place, Bordeaux R,. 
anilin-blue, or methyl-eosin ; but chiefly the first, then the iron-hsema- 
toxylin. The chapter on methods is well worth the attention of 
histologists. 
Hardening of Chick’s Egg in toto.f — As it is almost impossible to 
take out the contents of a fresh egg entire after the first week of incuba- 
tion, Mr. S. Hirota recommends that the egg should be patiently tapped' 
until the greater part of the shell is broken into small pieces ; these 
should then be separately removed, and the underlying shell-membranes 
left intact. 
If the egg has been in incubation less than two weeks, care should 
be taken not to injure the large blood-vessels of the allantois ; if they 
are injured, the blood should be coagulated by blowing at the point. At 
this stage, as the contents are still soft, a large piece of shell should be 
left to support the envelopes in their relative positions till they have 
become hardened in Kleinenberg’s fluid. Next day the fluid should be 
pipetted off and carefully replaced by alcohol. 
When the egg has been in incubation for more than two weeks*there 
is no danger of injuring the blood-vessels, even the inner shell-membrane 
can be removed without fear of bleeding if the whole be put in Kleinen- 
berg’s fluid for half an hour or even less. When the contents are entirely 
cleared from the non-cellular envelopes the specimen is put in the same 
fluid for half a day ; the fluid, when it has done its work, can easily be 
replaced by alcohol. 
In both cases yolk, albumen, and amniotic fluid should be removed, 
as these substances coagulate in alcohol, and cannot then be removed. 
Examination of Pedal Gland of Pulmonates.j: — M. E. Andre used 
the methods of teasing when fresh, and teasing after maceration in various 
reagents as well as that of sections. As a macerating reagent he found 
1 per cent, osmic acid and 1 per cent, bichromate of potash to be good, if 
used alternately for from two to seven days, when studying the glandular 
cells; for the epithelial cells of the excretory canal saturated solutions 
of boric and salicylic acids kept at a temperature of from 25° to 30° 
for two or three hours, and a 3 per cent, solution of chloral hydrate were* 
found to be good, especially if a suitable nuclear stain was added. 
* Arch. f. Mikr. Anat., xliii. (1894) pp. 423-758 (7 pis.). 
t Journ. Coll. Sci. Imp. Univ. Japan, vi. (1894) pp. 367-9. 
X Rev. Suisse Zool., ii. (1894) pp. 293-5. 
