ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
485 
thoroughly washed for 12-24 hours in 67 per cent, alcohol to which a 
little gum camphor was added to hasten the removal of the mercuric 
chloride ; so long as tincture of iodine is decolorised when added to the 
alcohol, the washing should be continued ; unless the chloride is entirely 
washed out, crystals will form in the specimen. For the outlines and 
relations of cells Ehrlich’s fluid gave good results, but for details of 
structure was generally found to be inferior. 
The castor-thyme method introduced by Fish was employed in 
sectioning. The object was imbedded in collodion. The hardened 
tissue was dehydrated for 12-24 hours in 95 per cent, alcohol, placed 
in 2 per cent, collodion for 1 day, 3 per cent, collodion for 1 day, and 
5 per cent, collodion for 1 day. The collodion was then hardened in 
chloroform for 1-3 hours and cleared in a mixture of castor oil and 
three parts of red oil of thyme. When transferred to the slide the 
superfluous oil was absorbed and the collodion melted with equal parts 
of alcohol and ether. The Ehrlich-Biondi stain gave excellent results, 
especially in a study of glands and leucocytes, because of its high selective 
power. The best results with a nuclear stain were found by the use of 
an aqueous solution of haematoxylin. 
Amitosis in Ovaries of Hemiptera.* — Herr F. Preusse fixed in 
concentrated cold sublimate (5-10 minutes) or chrom-osmio-acetic acid, 
after Flemming and Carnoy, or Kleinenberg’s picro-sulphuric ; and 
stained most successfully with haematoxylin. 
Histology of Trematodes.j — Dr. A. Schuberg, in his investigation 
into the histology of Trematoda, made use of the method of metliylen- 
blue staining, and prepared sections from carefully preserved material. 
In his staining experiments he washed out the flukes from a still warm 
liver by means of a fine brush, and conveyed them at once into a 
methylen-blue solution (1/3-1/4 per cent, methylen-blue plus 0*75 per 
cent, salt solution), which was warmed to about the temperature of the 
body, the solution being kept warm ; the objects were left in it for 
4-5 hours or longer. The best results, i. e. a staining of as many of 
the nervous elements as possible, were obtained with animals which 
were just beginning to die. For control observations he made use of 
sections. For the investigation of nervous elements he recommends the 
osmic acid-acetic method of v. Mahrenthal. The fresh flukes were killed 
in a 1 per cent, solution of osmic acid, which must be contained under 
a cover-glass supported by a wax foot, so that the animals may be kept 
well flattened out. After the removal of the cover-glass they were left 
for 6—12 hours in the osmic acid, so that it should completely penetrate 
them. They were then brought directly into the acetic acid, washed 
with water, and imbedded in paraffin. As all the tissues blacken com- 
pletely, the sections must not be too thick. 
Investigation of Gyrodactylus.* — To fix these parasites Dr. L. 
Katharincr made use of cold sublimate solution or of a solution as hot 
as 50°* This was succeeded by chrom-acetic acid and osmic acid, while 
borax-carmine and heematoxylin were the staining reagents. Control 
* Zeitsclir. f. wiss. Zool., lix. (1895) pp. 305-49 (2 pis.). 
f Arbeit. Zool. Zoot. Inst. Wurzburg, x. (1895) pp. 168-70. 
I Torn, cit., p. 128. 
