22 



Before going on to consider the results of the inoculation experi- 

 ments made with various specimens of milk, it may be well to glance 

 at the condition of the cows that have been under our control from 

 the time of the beginning of the experiments until they were killed, 

 or until the date of preparing this paper. 



The history of each cow, as far as we have been able to secure it, 

 bears out our assertion — as far as the examinations have gone, that 

 none of the udders were affected with tuberculosis — certainly so far 

 as gross appearances were concerned. This was true, also, in the 

 microscopic appearance of every case but one (No. 6, cow F). In 

 this case the gross appearances in the udder were healthy, except 

 that one quarter seemed to be slightly fibrous, and there wefe one or 

 two yellow spots which were seen to be. made up of fat under the 

 microscope. With a low power lens only a slight increase of fibrous 

 tissue was observable, and the oil-immersion was put on merely as a 

 matter of routine. One giant cell was discovered, containing a num- 

 ber of bacilli, but a careful search failed to i^how any others, or 

 any signs ol change, except the increase of fibrous tissue noted 

 above. So that the assertion is still true, that we have failed to dis- 

 cover any signs of tuberculosis that were easily recognizable in any 

 of the cows here recorded, and these include all we have had under 

 close observation. 



Those from which milk was used for inoculations that are not here 

 given had no signs that permitted of even a probable diagnosis by 

 skilled veterinarians. 



We also made an interesting series of experimental inoculations in 

 rabbits and guinea pigs with milk or cream from various cows, in 

 varying quantities and at different times. Of rabbits there were used 

 fifty-seven animals. Of these, five were inoculated with milk which 

 had turned sour, two died of intercurrent diseases in a few days 

 (coccidium oviforme), and of one the material was lost before the 

 microscopic examination was completed — so that eight animals are 

 to be rejected, leaving forty-nine upon which the results can be based. 

 Out of these, five were made more or less tuberculous, as proven by 

 microscopic examination, and in forty-four the results were negative 

 — that is to say. we obtained 5 : 49, or 10.2 per cent, of successes out 

 of all inoculations in rabbits. 



There were used thirty-three different spceimens from thirteen dif- 

 ferent cows— that is, there were 2o per cent. (3: 13) successful re- 

 sults from the cows used, and 15.15 per cent. (5 : 33) successful re- 

 sults from the specimens used. 



Positive results were obtained from 

 Cow P twice (at different times). 

 Cow L once. 

 Saunders cow twice (at different times). 



The results of the inoculations of guinea-pigs are more striking. 

 There were sixty-five animals used in all. Of these, nine were inoc- 

 ulated with sour" milk or cream, and two died in a day or two of other 



