212 QUEENSLAND AGRICULTURAL JOURNAL. [1 Mar., 1899. 
amount of money the English have expended in order to stamp out contagious 
pleuro-pneumonia. Their Act of 1890 orders the slaughter, not only of the 
sick and suspected, but also of all animals that have been in contact with the 
‘sick. In 1891 there were thus slaughtered, in different parts of England and 
Scotland, nearly 10,000 animals (of which only 800 were sick) ; post-mortems 
were made on these 10,000 animals, and 1,260 were tuberculous, or 123 per 
cent. In 1892 the operation was continued, but was brought to bear on much 
smaller numbers, pleuro-pneumonia being on the decrease. However, there 
were slaughtered 3,600 animals (of which 134 were sick), and of this number 
nearly 800 were tuberculous, or 22 per cent. This high proportion is due to 
the fact that the slaughtering operations were brought to bear on some of the 
most crowded aud anciently infected cowhouses in London, some of which had 
23 many as 50, 60, and 70 per cent. of their cows aifected with tuberculosis. 
Causes of Tuberculosis—Up to quite recently medical men, veterinary 
surgeons, and the public generally looked upon tuberculosis as a true type of 
hereditary diseases. Even at the present day stockbreeders will endeavour to 
bring forward, apparently, the most convincing evidence from their point of 
view to support this supposition ; but the statistics obtained from the various 
continental abattoirs disagree with this theory almost entirely; in fact, all the 
inspectors are of the one opinion that there is nothing more rare than tubercu- 
losis of the calf. Here are some figures demonstrating this point:—At the 
Munich abattoir 160,000 calves are slaughtered yearly on an average, and out 
of this number there have been found tuberculous—2 in 1878, 1 in 1879, none 
in 1880, none in 18381, and 2 in 1882. At Lyons, M. Leclere, who has taken a 
particular interest in this question, has only found 5 tuberculous calves out of 
400,000 slaughtered at the public abattoir. At Rouen, Veysierre has found 3 out 
of 60,000. At Berlin, Jobne has found 4 out of more than 150,000. In Prussia, 
from 1st April, 1892, to 31st March, 1893, there were slaughtered in the public 
abattoirs 6U0,501 adult cattle, of which 52,186 were tuberculous, or 8°68 per 
-cent.; and 914,216 calves, of which only 440 were tuberculous, or a little less 
than °04 per cent. To thoroughly appreciate these figures, it must not be 
forgotten, as Nocard points out, that everywhere the number of tuberculous 
-cows is infinitely greater than that of other cattle. 
Among the various hereditary and predisposing causes which may be 
regarded as factors to diminish the resisting properties of the animal tissues to 
the action of the tubercle bacillus, are unhealthy surroundings, close and ill- 
ventilated buildings, dark stables, insufficient or unwholesome food, breeding 
too young or too frequently, or late breeding, overfeeding to secure an 
abnormal production of milk—in fact, any treatment of cattle that tends to 
debilitate or over-stimulate—may be considered as a predisposing cause. These 
conditions, some of which are too often imposed, require the very serious 
consideration of the breeder of stud cattle, those engaged in raising store 
cattle, the producer of fat stock, the dairy farmer, and even the bullock-driver, 
all of whom are anxious to possess sound and healthy animals with vigorous 
constitutions. Stockbreeders should bear in mind that the predisposing cause 
can under no circumstances result in tuberculosis without action of the 
essential cause; and the tubercle bacillus is certain to produce its specific 
pathogenic effect in tissues that are impaired by hereditary or acquired causes. 
As for Koch, whose authority in the matter is undeniable, he declares that 
although he has conducted hundreds of most crucial experiments, he has never 
seen any of his female guinea-pigs, when tuberculous, transmit the disease to 
their offspring. According to him, hereditary tuberculosis finds its most 
natural explanation; for what the mother does transmit to its offspring is not 
the disease itself, but the predisposition or proneness to contract the disease. 
In other words, the offspring is born tuberculisable, not tuberculous. 
These well-established facts tend to prove that heredity plays a very small 
part, and contagion a great part, in the propagation of bovine tuberculosis, 
and that if the young born of tuberculous parents were protected from cohabi- 
station, and the ingestion of tubercular milk, the importance of heredity as @ 
