NINTH ANNUAL YEAR BOOK— PART X 483 
A considerable number of investigators, including Chauveau, Vagedes, 
Ravenel, de Schweinitz, Mohler, De Jong, Delepine, Orth, Stenstrom, 
Fibiger and Jensen, Max Wolff, Nocard, Arloing, Behring, Dean and Todd, 
Hamilton and Young, the German Tuberculosis Commission and Theobald 
Smith, have found tubercle bacilli in the bodies of human beings that 
died of tuberculosis, which proved to have about the same virulence for 
cattle as had the bacilli from bovine animals affected by the disease. 
Kossel, in a preliminary report, stated that the German commission 
had tested seven cultures of tuberculosis from cattle and hogs — four from 
cattle and three from hogs. Two of these cultures proved acutely fatal 
in cattle after eight to nine weeks; four of the cultures likewise produced 
a generalized tuberculosis, but which certainly had a more chronic course, 
while one of the cultures caused only an infiltration at the point of in- 
oculation, with some caseous foci in the adjoining prescapular gland and 
in one of the mediastinal glands, and there was lacking the spreading 
of the tuberculosis over the entire body, which they were accustomed to 
see after the injection of cultures of bovine tuberculosis. "Hence," says 
Kossel, "among bovine tuberculosis bacilli there can also occur differences 
with regard to virulence." 
The German commission also tested 39 different freshly made cultures 
from tuberculous disease in man. Nineteen of the cultures did not produce 
the slightest symptoms in cattle; with nine other the cattle exhibited 
after four months very minute foci in the prescapular glands, which were 
mostly encapsuled and showed no inclination to progess; with seven 
other cases there was somewhat more marked disease of the prescapular 
glands, but it did not go so far as a material spreading of the process to 
glands next adjoining. There were four cultures, however, w^hich were 
more virolent and caused generalized tuberculosis in the cattle inoculated 
with them. 
It would appear, therefore, that hereafter everyone must admit that it 
is impossible always to tell the source of a culture of the tubercle bacil- 
lus by its effects when it is inoculated upon cattle. One of the bovine 
cultures failed to produce generalized tuberculosis in cattle, and some 
of the human cultures did produce this form of the disease in such ani- 
mals. Moreover, while some of the human cultures caused no disease 
at all, others led to the development of minute foci in the prescapular 
glands, and still others to somewhat more marked disease of these 
glands. There were, consequently, four degrees of virulence noted in these 
39 cultures of bacilli from human sources and three degrees of virulence 
in the seven cultures from animal sources. 
Now, if v.e accept the views of Koch as to the specific difference be- 
tween human and bovine tubercle bacilli, and that the human bacilli pro- 
duce only localized lesions in cattle, while bovine bacilli produce general- 
ized lesions in these animals, must we not conclude that the one non- 
virulent bovine culture was in reality of human origin, and that the ani- 
mal from which it was obtained had been infected from man? That is a 
logical deduction, but reverses the dictum laid down at London that 
human tuberculosis is not transmissible to cattle. Again, how are we to 
explain the human cultures of medium virulence? Are they human 
