EXPERIMENT STATION BULLETINS. 



645 



satisfy the writer that the presence of the antibodies in human sera 

 are due to the ingestion of infected millv, and might indicate active 

 infection or merely a passive immunity due to the absorption of anti- 

 bodies from the milk. 



To determine whether or not Bad. abortus antibodies could be made 

 to appear in the sera of adults by ingestion of infected milk a feeding 

 experiment was arranged. To obtain milk for this experiment cows 

 were selected whose milk had a high Bad. abortus antibody content, and 

 caused Bad. abortus lesions and blood reactions when five cubic centi- 

 meters were inoculated into the abdominal cavity of guinea pigs. Dur- 

 ing the twelve weeks of this experiment the milk was tested twice a 

 month. The highest and lowest antibod^^ content of the milk during this 

 period is shown in Table II. 



TABLE II.— SHOWING THE BACT. ABORTUS ANTIBODY CONTENT OF THE MILK 



FED IN WORK REPORTED IN TABLE III. 



During the experiment shown in Table III each person was drinking 

 daily for a period of eight weeks about a pint and a half of the milk 

 shown in Table II. The antibody content of the human sera at the 

 start, at the highest concentration during the test, and four weeks after 

 the individuals had ceased to. drink the milk, is shown. 



