Nc. 6. DEPARTMENT OF AGRICULTTTttE. 301 



COMPARATIVE VIRULENCE OF BOVINE CULTURE H AND HUMAN CUL- 

 TURE K FOR PUPPIES AND PIGS WHEN INTRODUCED THROUGH THE 

 ALIMENTARY TRACT. 



Puppies. — Four puppies eighty weeks old, from the same litter, were 

 selected, two of whicb received a suspension of milk of bovine cul- 

 ture II and two a similar suspension of human culture K, equal 

 amounts being given on ten days, six days in succession, with an in- 

 terval of seven days, then four days in succession. The regular food 

 was sterilized milk, bread and boiled beeef. 



Only one of the four puppies died, one of the two which received 

 the human cuKure K, death occurring after fifty-seven days. There 

 was a generalized tuberculosis, most marked in the lungs and liver. 

 The other puppy was killed after eighty-five days. The only lesions 

 found were small cheesy nodules on surface of one lung, iti parotid 

 and mesenteric glands. 



The two puppies fed vvith bovine culture H showed no ill effects 

 whatevei", and were killed on the eighty-fifth and eighty-seventh 

 days, respectively. Both w-ere in good condition, the only lesions 

 found being m the parotid and mesenteric glands, which contained 

 minute caseous areas, none larger than 2 mm. in diameter. 



Pigs. — As with the puppies, four pigs from the same litter, eight 

 weeks old, were taken, two being fed with human culture K, and 

 two with bovine culture H, equal amounts of a suspension in sterile 

 water being soaked into bread and given for ten days with a«i inter- 

 mission of only one day. The tegular food was sterilized milk, 

 ground oats, bran and cornmeal. 



All four of the pigs died, the average life of the two fed with 

 human bacilli being one hundred and eighteen and a half days 

 against one hundred and a half days for the two which received the 

 bovine culture. One pig of each pair lived one hundred and twenty- 

 three days, dying on the same day. The total difference in gain of 

 weight was only half a pound. All showed, postmortem, a gener- 

 alized tuberculosis. 



While some differences were noticed in the extent of the disease 

 in various organs, it cannot be said that these were such as to indi- 

 cate a greater virulence of one culture than the other. In all the mes- 

 enteric glands were extensively diseased, while in one only, fed with 

 bovine bacilli, was there ulceration of the mucous membrane of the 

 intestine. Three of the four showed tuberculous ulceration of the 

 tonsils. The remaining one presented no gross changes in this 

 gland, but, microscopically, areas of necrosis, apparently in the lymp- 

 follicles, were found, and sections stained with carbol-fuchsin re- 

 vealed large numbers of tubercle bacilli. The two pigs which lived 

 longest, one bovine and one human, both had extensive involvement 



