388 
FOURTH INTERNATIONAL VETERINARY CONGRESS 
cadaver, is no more difficult than that of glanders, especially 
when the latter affects a latent form. The diagnosis of glanders 
is, even in this case, often more complicated than that of 
tubercles in cattle. Upon the cadaver, it is much easier to 
make out this disease, notwithstanding the numerous forms of 
alterations that may present themselves. Everywhere marks are 
found of the influence of a foreign agent, which has determined 
lesions in all the parts where it has deposited itself. It may 
happen that errors may be made in the appreciation of the 
lesions observed, for we are not infallible. But this would be 
an exceptional case. An absolutely fixed character cannot be 
given to the phthisis of the ox; a recent and very important dis¬ 
covery has, however, thrown a strong light upon the question, 
and so to speak, given us a criterion of tuberculosis. The 
presence of special germs, the baccillus of Mr. Koch, observed 
with the microscope, finally settles the question of the diagnosis 
in doubtful cases. 
Mr. Lydtin then passed to the second point of the question, 
and treated of the propagation of tuberculosis. He said that this 
disease exists quite extensively in all countries of the globe, and 
that almost everywhere it has reached considerable proportions. 
On this account, it well deserves the name of universal pan¬ 
zootic. In view of its extensive existence, Mr. Lydtin proceeded 
to inquire into its cause, which he attributed first to, heredity, 
and secondly to contagion. 
Basing his remarks on observation and experiment, he con¬ 
sidered it as demonstrated that these are the principal agents in 
the propagation of the disease. Contagion has been both ad¬ 
mitted and denied for a long period of time, but long continued 
experiments had at last established the infectious character of the 
disease. 
The agent of transmission penetrates the organism through 
the lymphatift blood vessels, but propagates slowly. The lesions 
produced by the tuberculous germs are first localized, and 
isolated from the surrounding tissues. They then, by degrees, 
spread through the organism, while at the same time older 
lesions undergo successive transformations ; they are at first hard 
