16 STORRS AGRICULTURAL EXPERIMENT STATION. 
toms are absent. As would be expected, the amount of tuber- 
culosis detected by this means is in excess of that indicated by | 
the slaughter-house records. Tuberculin, as we shall see 
presently, detects incipient cases, and many a case that would 
be entirely overlooked by the most careful inspector of flesh. 
Moreover, it must be remembered that in no country has there 
been anything like a general inoculation of the animals from 
which could be obtained average results. Only such herds are 
generally tested with tuberculin as are somewhat suspicious. 
The results obtained from such a herd would be largely in ex- 
cess of those which would be obtained if tuberculin were used 
upon all animals indiscriminately. 
Considering, then, the uncertainty of the methods of 
getting statistics, it is not surprising to find that the conclusions 
as to the prevalence of tuberculosis among cattle are at wide 
variance with each other. The estimates run all the way | 
from zero in some herds to one hundred per cent. in others, 
and the attempt to draw any average from such widely 
varying results is extremely fallacious and misleading. 
Nevertheless, taking together all of the facts derived from all 
sources, it is possible at all events to get some idea as to the 
relative amount of tuberculosis in different places and under 
different conditions. 
It is found that the amount of tuberculosis among cattle 
varies with the climate. In the southern countries of Europe, 
like Italy, Spain, Switzerland, the amount of tuberculosis 
among cattle appears to be comparatively small, although this 
may be partly because it is less studied. ‘The same is true on 
the whole continent of Africa, and to a considerable extent, 
also, with the cattle in the western plains of the United States. 
On the other hand, the amount of tuberculosis among the 
northern countries of Europe, Germany, Denmark, Belgium, 
Great Britain, is relatively large. Statistics are apparently 
showing to-day that the amount among our own herds in the 
eastern section of the United States is also large, possibly ap- 
proaching in its extent that of some of the countries in Europe. 
The variation in the amount of tuberculosis is to a certain 
extent parallel with the amount of outdoor life of the animals. 
In the southern countries of Europe, in Africa, and in our 
western territories, the animals are kept largely out of doors, 
and so long as they do not go into the stall and remain housed 
they are only slightly liable to this disease. In the countries, 
however, where the animals are kept indoors a large propor- 
