304 ANNUAL REPORT OF THE Off. Doc. 



of the joints, so that for several weeks before death walking was 

 almost impossible. 



The result of this experiment is inconclusive as far as the puppies 

 are concerned, except as showing that they are readily infected 

 through the alimentary tract. The pigs showed practically an equal 

 susceptibility to the two cultures. The ease with which they were 

 infected, and the extent of the lesioos produced in so short a time, 

 were both striking features, and should serve to put farmers on their 

 guard against feeding (heir swine on milk from tuberculous cattle. 

 In Pennsylvania we have observed several instances in which neglect 

 of this precaution has led to considerable loss. 



The cultures included io Table III were all recovered from animals 

 which had been inoculated or fed with cultures H and K. Their 

 virulence was tested only for rabbits and guinea-pigs. The most 

 striking thing to be noticed in the results is the increase in virulence 

 in the human bacillus recovered from the hogs K (D) and K (E). 

 The average length of life for guinea-pigs after inoculation with the 

 original culture K was thirty-eight days, while the rabbits were 

 killed after eight months and twenty-three days, showing success- 

 fully resisted infection. On the other hand, the culture recovered 

 from the hogs killed guinea-pigs in twenty-nine and one-half and 

 thirtv-two and one-third davs, and rabbits in seventv-one and one- 

 half days respeclivelj', showing a virulence for those animals which 

 corresponds to that seen in bovine cultures. 



Culture H (E) was recovered from a nodule oo the hand of Dr. S. 

 H. G., who accidentally inoculated himself while making a post- 

 mortem on one of the goats which had succumbed to the original 

 culture H. Particular interest attaches therefore to this culture. 

 No marked difference can be detected in the viruleoce of this culture 

 as compared with the original. 



Considerable difference has been noted in the readiness with which 

 the recovered cultures grew in Ihe early generations. H (A), H (B), 

 H (D) and H (F) all grew vigorously from the start, the three last 

 growing without any stirring of the tissue on the original tubes, 

 while H (G) grew on tubes sealed with paraffin, a result which I 

 have been able to obtain only with the human bacillus, with this ex- 

 ception. The morphology of all the recovered cultures correspond 

 closely to the original. 



