HISTOLOGY OF THE MAMMARY GLAND. 
281 
because there has been so little done up to the present time to dissolve 
this question. 
The material for the following experiments were from the mam¬ 
mary glands of six cows slaughtered on account of perlsucht. 
In one case I found by an histological investigation of the mam¬ 
mary gland, lymphosarcomatose neoplasms in a very premature stage; 
in the other five there was merely catarrhal inflammation of the lacteal 
ducts and chronic interstitial mastitis. 
1st case, metastatic lymphosarcomatose nodules in the mam- 
\ 
MARY GLAND. 
The animal was nine years of age, and by dissection we found 
nodules (Perlknoten) varying from the size of a pea to a hazel-nut, upon 
the pleura, in the lungs and bronchial glands. 
There discharged from the sinus-lactiferi and ductus-lactiferi, a 
yellow pus-like fluid, containing small flakes. From a microscopal in¬ 
vestigation of this fluid I discovered a large quantity of round cells 
(pus-corpuscles) ; also a number of white blood corpuscles, which con¬ 
tain one or two small nuclei, or a single large one. The above men¬ 
tioned flakes appeared, under the microscope, as a conglomerate of 
round cells, which were held together by a granulose mass, soluble in 
acet. acid. The tissue of the mammary gland is compact, especially in 
the superior part of the gland. The interstitial connective tissue is very 
much developed, particularly in the vicinity of the “ vena mammaria 
postica,” where one distinctly observes white striae of connective tissue ; 
some parts of the gland lobule are atrophied, whilst other parts are 
elevated above the level of the cut surface, in the form of globules, about 
the size of peas; here and there one sees spots resembling adipose tis¬ 
sue, instead of the white lobule. 
The lymphatic glands in the neighborhood of the “ vena mammaria 
postica” are in a hypertrophic condition, and contain a great number of 
nodules, which cannot be distinguished from those on the pleura ; the 
parenchyma has almost entirely disappeared in the center of these glands, 
and replaced by nodules (perlknoten), and we can only here and there re¬ 
cognize remnants of the glandular tissue in the peripheries of the gland 
between the nodules. 
Different parts of the mammary gland were submitted to examina¬ 
tion ; some in the fresh condition, others after being hardened in Muller's 
fluid, or a 36 per cent, solution of alcohol. Some of the microscopical 
