632 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
•were then hardened in picrosnlplinric acid or picrosalt solution ; the 
dead and hardened worms retained the shape of the living worm almost 
perfectly. Lactic acid acts too slowly on adults to he of use for them. 
Study of Endoglobular Parasites.* — M. A. Labbe prepared a con- 
venient staining reagent by putting on the slide a drop of methylen-blue 
1 part, water 100 parts, and chloride of sodium 0*75, which was drawn 
under the cover-glas> by blotting-paper. One per cent, solutions of acetic 
carmine and of methylen-green also gave good results. For fixing 
Gymnosporidia the following method was used : — Flemming’s fluid, then 
five minutes in distilled water ; after drying, a solution of one drop of 
acetic acid in 20 ccm. water ; then in picric solution (picric acid, SO parts 
of concentrated aqueous solution, 30 parts distilled water, and 1 part 
glacial acetic acid) ; after being in this for a day, the preparation was 
washed in absolute alcohol. 
Various staining reagents were used; a triple coloration was effected 
with Delafield’s haematoxylin, acid fuchsin or Bengal rose, and aurantia ; 
several methods of staining must be tried to find the key to the structure 
of these organisms. 
Botanical Microtechnique.! — Herr F. Eosen after pointing out that 
the contraction of vegetable tissue during imbedding is by the ordinary 
method often unavoidable, advises the following procedure. The objects, 
thoroughly dehydrated in absolute alcohol, are successively transferred 
(1) to a mixture of equal parts of absolute alcohol and bergamot oil ; 
(2) to pure bergamot oil ; (3) to a mixture of equal parts of bergamot 
oil and paraffin; (4) to paraffin with melting-point 45°; (5) to paraffin 
with melting-point 56°-58° for 24 hours. In stages (3) and (4) the 
fluids should be kept at 48°, in stage (5) at 60°. In order to make the 
sections adhere to the slide they are placed while still in paraffin on a 
drop of fluid which can be evaporated completely. The fluids suitable 
for this purpose are distilled water or 50 per cent, pure alcohol. 
Evaporation at room temperature is slow, but can be rapidly and safely 
accomplished at 32°-36°. When the fluid has completely evaporated 
the section adheres firmly and there is no damage to the finer .structures. 
The paraffin is then dissolved out with xylol. The three temperatures 
32°-36°, 45° and 60° are obtained in a tripartite paraffin oven devised 
by the author. In this apparatus sections 5-10 /x thick are made to 
adhere in about 12 hours. Of course the alcohol must be completely 
evaporated before the sections are treated with xylol, otherwise they will 
get free. 
Preparing Megaspore and Female Prothallium of Selaginella.J:— 
The great delicacy of these objects makes imbedding difficult. As a fixing 
process Herr E. Heinsen recommends the action, for ten minutes, of a 
mixture of 1 gr. chromic acid, 0*4 gr. osmic acid, and 0 * 4 gr. acetic acid 
in 200 gr. water ; or a three minutes’ treatment with a 1 per cent, solution 
of sublimate. The collapsing of the protoplasm of the spore was avoided 
by this method. 
* Arch. Zool. exper. et gen., ii. (1894) pp. 57-61. 
t Schlesische Gesellsch. f. Vaterland. Cultur, Jahresbericht, 1893 (Bot. Sec.) 
pp. 8-11. X Flora, lxxviii. (1894) pp. 468-9. 
