TUBERCULOSIS. 361 



year by year, in such a way as to seem to indicate an alarming 

 increase in the past fifteen years. But a considerable part of 

 this increase is clearly due to increased experience and care- 

 fulness in inspection. To what extent this factor explains it, 

 and to what extent there is an actual increase in the disease, 

 no one can pretend to say. 



It is therefore impossible to state whether bovine tubercu- 

 losis is rapidly increasing, or slowly increasing, or remaining 

 stationary. It has been almost universally recognized, how- 

 ever, that an increase from 1 1 per cent, to 33 per cent., in the 

 returns given in the same locality for a period of 7 years (oc- 

 curring in Leipzig), indicates something more than increased 

 carefulness of inspection. The practical uniformity with which 

 these reported percentages have increased in the last years 

 has led to the general belief that the disease is actually in- 

 creasing among our herds. 



But although no definite statistics can be given, either as to 

 the prevalence of the disease or its increase, it is evident that 

 bovine tuberculosis is abundant enough, and that it presents a 

 very serious problem to the farmer. Entirely independent of 

 the question of its relation to human tuberculosis, the disease, 

 as it exists among cattle, is a serious menace to the dairy in- 

 dustry. The amount of financial injury that it does to the 

 farmer each year is very great far in advance of that pro- 

 duced by the much-dreaded anthrax. The insidiousness with 

 which it finds its way into and spreads through the whole 

 herd, even before the farmer is aware of its presence, the large 

 number of cattle rendered worthless through its agency, 

 especially among high-bred and valuable animals, the sus- 

 picion which it throws upon the milk supply, the injury that it 

 does to the animal which is to be used as food, the great cost 

 of tuberculosis legislation by the different states, all these serve 

 to emphasize the seriousness of the problem. Nothing can be 

 of more importance to the farmer than the discovery of some 



