Annual Report for 1908 of Royal Veterinary College. 291 
and others) that in many cases of human tuberculosis the 
lesions contain tubercle bacilli that have only a feeble virulence 
for cattle, it was natural to expect that cultures of such bacilli 
might prove serviceable as a “ vaccin ” for immunising bovine 
animals. The idea was taken up in Germany by Von Behring, 1 
at whose instigation a method of vaccinating calves against 
tuberculosis has been practised on a comparatively large scale. 
On a smaller scale, and by slightly modified procedures, young 
cattle have also been immunised against the disease in France, 
the United States of America, and other countries. A short 
account of this method of vaccinating animals against tuber- 
culosis was given in the Annual Report for 1905, and from a 
review of the evidence then available the opinion was expressed 
that the method was comparatively safe, and that it might 
prove of great value as a means of combating bovine tuber- 
culosis. In the interval a very large body of further evidence 
bearing on the safety and efficiency of the method has been 
obtained, and a confident opinion regarding its merits and 
demerits now appears to be justified. Briefly, it may be said 
that this method, when properly carried out, is devoid of 
danger for the animals operated upon, or at least is not attended 
by any risk which an owner need hesitate to accept provided 
he is assured that the operation is a valuable one in its ultimate 
results. And with regard to the latter point, it may unhesi- 
tatingly be asserted that the method is valuable, in the sense 
that young cattle can thereby be given a high degree of 
immunity against tuberculosis. These statements are not 
based entirely on a review of the foreign literature (already 
considerable) on the subject, but partly on the results which 
have been obtained in three herds in this country, in which the 
young cattle have been vaccinated by this method. In two of 
these only a small number of calves were operated upon, and 
as these animals were not subsequently tested with tuberculin 
they have not furnished any evidence as to the actual protective 
value of the method. They are referred to here only because 
they went to show that the operation was without danger. 
The third herd was one of valuable pedigree Shorthorns, and 
as, with few exceptions, all the calves have been vaccinated for 
three years in succession, and two seasons’ calves have been 
subsequently tested with tuberculin, the results are of greater 
value as an indication alike of the safety and of the efficiency 
1 Strictly speaking, Von Behring’s experiments were apparently not 
inspired by the idea that the tubercle bacilli found in human lesions might 
immediately prove serviceable for vaccinating cattle. He appears to have 
thought that such bacilli might be modified in virulence by passing them 
through such animals as goats and guinea-pigs, and thus made suitable for 
vaccinating cattle. 
