24 



culosis appeared in any of these, their ill health cannot come in as a 

 disturbing factor in the results. 



The results obtained from certain feeding experiments with calves 

 show that there were thirteen calves used, and fed for varying lengths 

 of time with milk from cows affected with tuberculosis, but not of the 

 udder. Of these, the material was thrown away from one before the 

 microscopic examination, and this should be rejected in the final 

 results. Of the remainder, there were five positive results obtained 

 and one suspicious. The latter is counted as negative, for the reason 

 that, although giant cells and granulation tissue were seen, no bacilli 

 were found. There were, therefore, five out of twelve positive re- 

 sults, or 41.66 per cent. It should also be said that of those counted 

 as negative three sets of specimens were suspicious, but were hastily 

 examined for the purpose of this paper, so that a more careful search 

 may very probably increase the percentage of successes. 



In the series of feeding experiments on one set of pigs, the milk 

 being given to them from the same cows as before, there were seven 

 pigs used in all, from one litter and healthy parents. Of these, 

 examination showed negative results in two, positive results in two, 

 one was subjected to a very hasty microscopic examination, and the 

 material from two was thrown away— a mistake, as was shown by the 

 results of the microscopic examination of the material from No. 3. 

 There are to be counted, therefore, only five, giving as successful 

 results 40 per cent. 



By the cover-glass examinations we have shown that the milk con- 

 tains infectious material in ten cows out of thirty-five from which the 

 milk was examined for bacilli — that is, in 28.57 per cent. We have 

 also shown that the milk was infectious, by inoculaton experiments, in 

 seven out of fourteen of the cows from which the milk came — that is, 

 50 per cent. And we have shown the infectious nature of the milk by 

 ocular demonstration and successful inoculation from the same speci- 

 mens in five cows out of fourteen used — or, 35.7 per cent. 



These Results are, to a certain extent, preliminary — that is to say, 

 they are but part of the work upon this subject which is being done 

 under the auspices of the Massachusetts Society for the Promotion 

 of Agriculture. The work will not be completed, at any rate, until 

 next year. 



They show, however : 



1st, and emphatically, that the milk from cows affected with tuber- 

 culosis in any part of the body may contain the virus of the disease. 



2d. That the virus is present whether there is disease of the udder 

 or not. 



3d. That there is no ground for the assertion that there mnst be a 

 lesion of the udder before the milk can contain the infection of tuber- 

 culosis. 



4th. That, on the contrary, the bacilli of tuberculosis are present 

 and active in a very large proportion of cases in the milk of cows 

 affected with tuberculosis but with no discoverable lesion of the 

 udder. 



