116 
B. KOCH. 
lupus hypertrophicus) success was obtained in getting reniculturen of bacilli, 
which have also been used for the successful inoculation of animals. 
B.—TUBERCULOSIS IN ANIMALS. 
By the study of the appearances under which tuberculosis runs its course, 
in the various sorts of animals, the noteworthy fact is manifest that tuberculosis 
conducts itself differently in the case of almost every species. However striking 
this fact at first appears, it nevertheless corresponds to the observations made 
in regard to other bacteria diseases. So, inflammation of the spleen in a similar 
manner is different in different animals ; septicamie of mice, conditioned upon 
very small bacilli, offers another example, for when it is inoculated it kills 
mice, but in rabbits only causes an erysipelas-like disease confined to the 
skin. 
Until now no warm-blooded animal is known which is entirely unrespon¬ 
sive to the infection of the tuberculous virus, and one may therefore expect 
that many varieties will show themselves in the anatomical aspect of tubercul¬ 
osis in the various species of animals. 
However various the forms which the symptoms of tuberculosis may take 
in single species, and however little one may be inclined to explain human 
phthisis and a tuberculosis of a guinea pig caused by inoculation as the same 
sort of disease, nevertheless between these extremes there are found, partly in 
the same species, still more in other species, transitional forms of tuberculosis 
which cause the apparent gulf to vanish. But the complete unity of the tubercul¬ 
ous processes of different species of animals shows itself to be irrefutable when 
we look away from the constitution of the tuberculous organs as seen by the naked 
eye, and from the secondary changes in the same, such as caseous degeneration 
and calcination, and keep to the primary structure of the tubercle,which, as we 
have already seen, repeats itself with typical regularity in all the various proces¬ 
ses in man, and equally so in the apparently so different forms of tuberculosis in 
the various species of animals. The differences in the tuberculosis of different 
species of animals which most attract the eye concern only those secondary 
changes which in the one case lead to wide-spread coagulation-necrosis with¬ 
out caseous degeneration (liver and spleen of guinea pigs); in another to rapid 
softening and the formation of a thinly liquid, pus-like secretion (tubercle of 
the monkey); further to transformation into hop-like caseous substance (tuber¬ 
culosis of man); to simultaneous calcination and caseous degeneration (pearl 
distemper of cattle); to the formation of hard swollen masses with deposited 
lime “ concrementen ” (tuberculosis of the fowl)—and so forth. The primary 
changes in all these cases are histologically exactly alike. Somewhat the same 
is true in regard to the formation of pus in various animals. So the pus formed 
in consequence of a simple inflammation in the rabbit and the fowl has an en¬ 
tirely different constitution than that of man, and yet in this case one would 
not speak of different sorts of pus formation. 
It would lead too far if the special peculiarities of every single kind of 
animal should be described in detail, and I shall therefore be obliged to confine 
myself to a brief characterizing of the different forms. 
