es a as 
TUBERCULOSIS” IN CATTLE, 23 
a doubt that the transmission of tuberculosis from the animal 
to the offspring, while it is of rare occurrence, occasionally 
does occur. This has been proved in the case of cattle by the 
discovery, in the first place, of the disease in new-born calves, 
and, secondly, by the discovery of the disease even in the 
embryo calf before birth. It is of course easy to understand 
how the tuberculosis germs which are present in the mother 
may find entrance through the uterus into the embryo before 
birth, and if so, congenital tuberculosis is certainly a possibility. 
The discovery of the disease well advanced in new-born ani- 
mals and the discovery of well attested cases of the disease in 
the embryo settles the matter beyond question, so that one can 
no longer doubt that the disease may be congenital. 
But, while this is true, the cases of congenital tuberculosis 
are so rare that they may be almost neglected in con- 
sideration of methods for preventing the distribution of 
the disease. The vast majority of calves born from tuber- 
culous mothers are healthy and show no signs of the disease 
at birth. Whether they are more subject to subsequent in- 
fection than are the calves of healthy animals is still, perhaps, 
uncertain. It is a general belief that in the human race the 
children of tuberculous parents are more likely to take the dis- 
ease than children of other parents. ‘This is at all events a 
possibility, and perhaps we may say a probability, among ani- 
mals as well as man. ‘The fact that an animal has yielded to 
the disease would indicate that it has less resisting power 
than another animal that has not thus succumbed. It would 
be natural to suppose that this resisting power, being a result 
of the general vitality of the animal, might be transmitted to 
the offspring. Hence it would follow that offspring from 
tuberculous animals would be more likely to yield to the in- 
fection than the offspring of non-tuberculous cattle. But this 
is not yet demonstrated. 
Tuberculosis is now well known to be a contagious disease, 
and that it in some way passes from individual to individual is 
beyond doubt. That it extends through a herd of cattle from 
one infected individual to others appears also to be well at- 
tested by many instances. Nearly every farmer will recall 
cases where the introduction of a single tuberculous animal 
into a herd has been the cause of the spread of the disease 
through the herd until a considerable portion of the animals 
have been infected. It is certainly a general belief among 
practical agriculturists, and among scientists as well, that this 
