ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
563 
careful washing, it is then stained with a moderately concentrated solu- 
tion of congo-red, and finally, after careful washing, placed in paraffin. 
A good staining of membranes may also be effected by successive treat- 
ment with iron salts and potassium ferrocyanide, or with tannin and 
ferric chloride. 
Metachromatism of Parasitic Sporozoa and Carcinoma Cells.* — 
Dr. J. Ssudakewitsch states that in 150 cases of cancer the number of 
sporozoa was very variable, but only in six cases were they absent alto- 
gether. Associated with undoubted Sporozoa were forms simulating 
nuclei, and white blood-corpuscles, and from the appearances it became 
sometimes difficult to discriminate between the parasite, alterations of 
the nuclei, invaginated cancer cells and leucocytes. The author here 
gives the result of observations on the colour assumed by the Protozoa as 
contrasted with the tissue cells. 
(1) The preparations stained with Ranvier’s haematoxylin were 
fixed with 1 per cent, osmic acid, and after having been washed in water 
were placed in Muller’s fluid for 3, 4, to 6 days, and afterwards hardened 
in alcohol increased in strength from 70° or 96°. The preparations had 
a grey look. 
The nuclei of the connective tissue cells, leucocytes, and cancer cells 
are stained a dirty violet, while all but a few of the Sporozoa were a 
pure violet (metachromatism). 
(2) Objects stained with safranin were fixed in Flemming’s fluid, 
and after soaking in water for 1, 2, 3, or 4 days were immersed in a 
saturated watery solution of safranin and having been differentiated 
with alcohol acidulated with HC1 or HN0 3 , mounted in the usual way. 
The preparations were brownish, and the resting as well as the mitotic 
nuclei of the cancer cells were of the usual red colour. The amoeboid 
Sporozoa, the inter- as well as intracellular, had a brownish-yellow hue ; 
while all the capsulated forms were violet (not a pure but a dirty 
tone). 
(3) Methylen-blue preparations were taken from Flemming’s fluid 
or from alcohol and immersed for 24 hours in a saturated anilin- 
water solution of methylen-blue. Thus prepared the tissue cells were of 
an olive-green colour and the Sporozoa blue. In one case, by after- 
staining with eosin, some of the Sporozoa were stained violet, the tissues 
being of a pale rose tint. 
The illustrations given are extremely effective. 
Protozooid Appearances in Carcinoma and Paget’s Disease.]- — Dr. 
L. Torok considers that the appearances observed in carcinoma cells and 
Paget’s disease are those of degeneration affecting the cell-plasma and 
nucleus, and giving rise to very complicated figures. Only by numerous 
methods of staining can the deceptive appearances be properly distin- 
tinguished. The tissue should be fixed in absolute alcohol, 5 per cent, 
sublimate alcohol, Flemming and Demarbaix’s fluid, and stained with 
different solutions of carmine, hmmatoxylin, and safranin. 
* Centralbl. f. Bakteriol. u. Parasitenk., xiii. (1893) pp. 451-5 (1 pi., colrd.). 
f Monatsbl. f. Prakt. Dermatol., March 1, 1893. See Centralbl. f. Bakteriol. u. 
Parasitenk., xiii. (1893) p. 496. 
