183 
osmium-copper-hematoxylin stain having failed completely to bring 
them into view, while the silver method gives no indication that they 
are present. 
April 28% 1893. 
Literature cited. 
1) PFLuEsER, Arch. f. Physiologie, H. 9—10, 1869. 
2) NEsTERowsKy, Virchow’s Arch., Bd. 68, 1875. 
3) MıurA, Virchow’s Arch. Bd. 97, p. 142, 1884. 
4) Martinorrr, Gaz. med. di Torino, p. 100, 1889, 
5) BERKELEY, Pathologist and Bacteriologist, London, March 1893. 
6) Idem, Neurol. Centralblatt, 1892. 
7) Matt, Abhand. d. Math.-phys. Gesellschaft d. Wissens, Leipzig, 1891. 
8) Pat, Jahrbiicher d. Wiener Aerzte, 1888. 
9) Marz, Einfluß d. Syst. d. Vena portae etc., Arch. f. Anat. u. Phys. 1892. 
Il. The Gall Capillaries of the Rabbit’s Liver. 
The black tinction of the gall capillaries depends apparently, not 
on any staining of a membrane surrounding their lumen, but upon a 
chemical combination of the silver chromate with their contents. In 
the biliary ducts the lumen is ordinarily empty, but sometimes there 
appear black plugs running over considerable intervals of space in 
the lumen, which is the gall blackened by the metallic salt. The 
epithelial cells and lining membrane remain perfectly transparent, and 
stand out in sharp contrast with the black plug conforming in contour 
to the undulosities of the inner margin of the canal. 
Like every thing else that permits the impregnation by the chro- 
mate of silver, the staining of the gall capillaries is somewhat irre- 
gular: here and there in a microscopic field, clear spaces may be 
seen, where no capillary is impregnated, and rather frequently a stem 
or a branch of a capillary may be seen to end suddenly, where in 
other places it is perfectly stained, marking a defect in the staining. 
The liver of the rabbit is a semi-tubular gland, and according to 
the manner in which it is cut, different appearances with the capillaries 
are noticed. In sections where the cells of the gland are cut cross- 
wise, the microscopic field appears covered with a network of poly- 
hedral lines conforming closely to the shape of the liver cells (fig. 15), 
with but few breaks in their continuity, and these artificial ones; but 
where the section is so cut as to show the columnar arrangement of 
