19171 VETERINAEY MEDICINE. 481 



blood of the individuals and no untoward effects observable. In this experi- 

 ment negative milk to which 10 cc. of a 48-hour culture of B. abortus was 

 added was consumed in quantities of 1 pint per day for a period of six weeks. 

 " There seems to be little evidence to warrant a statement that B. abortus in 

 milk is either pathogenic or antigenic to any marked degree for the human adult 

 at least." 



Further experiments were conducted in which guinea pigs were fed on 

 naturally infected milk and the results were again negative. " We feel, there- 

 fore, that there is not suflicient evidence to condemn positive milk as dangerous 

 to guinea pigs by ingestion, since it has shown no pathogenic action and only 

 slight antigenic action." 



Pregnant and nonpregnant rabbits were fed with naturally infected milk for 

 a period of 124 days, the serological results being negative, and no lesions being 

 found in the animals on autopsy. In anotlier series six animals were fed non- 

 infected milk plus a culture of B. abortus daily. Two litters of young were 

 born to each rabbit during the experiment, but no abortions occurred in any 

 of the animals, nor were any lesions found on autopsy. It is concluded that 

 positive milk is not dangerous to rabbits by ingestion, since no pathogenic 

 action and only a very slight antigenic action results therefrom. 



Calves were fed with naturally infected and noninfected milk at the rate of 

 1 gal. of milk twice daily to each calf for a period varying from five to 14 

 weeks. From the results obtained it is concluded that " there is no connec- 

 tion whatever between the feeding of infected or noninfected milk and the 

 matting and staining of the sexual hairs of newborn calves. That B. abortus 

 antibodies develop in calves as a result of ingesting naturally infected milk 

 seems to us to be a demonstrated fact, but the cause and significance of the ap- 

 pearance of the antibodies can not be explained until further development of 

 the studies on the calves. The antibodies may be due to an active infection, 

 they may be due to an active immunity, or they may be due to a passive trans- 

 mission of the antibodies present in the milk. The possibility of infections 

 being acquired in utero seems to us to be a phase of the abortion question that 

 should be given as much attention as other possible modes of infection. Since 

 we have found that 16 per cent of the 12 calves used in this experiment pos- 

 sessed B. abortus antibodies at the thne of birth, and that the antibodies per- 

 sisted for many weeks after birth, we conclude that the control of the disease 

 must begin with a study of the calf at the time of birth." The experiments are 

 described in detail. 



A further experiment is reported which shows that milk containing B. 

 abortus antibodies is highly bactericidal toward the organism. " Therefore 

 milk containing B. abortus antibodies that has been heated at a sufficient tem- 

 perature to kill the organisms and not the antibodies should be looked upon as 

 being beneficial to newborn calves. The milk containing antibodies should 

 give the calf a passive immunity during its early development." 



The significance and duration of immunity in bovine contagious abortion, 

 A. AscoLi {Ztschr. Infektionskrank. u. Hyg. Haustiere, 11 (1915), No. S-Jf, pp. 

 156-169). — The results of experiments in which guinea pigs were inoculated 

 with Bacillus abortus which had been killed with ether, followed by the in- 

 oculation of living cultures, are reported. After various periods of time the 

 animals were killed and the spleen examined bacteriologically for the micro- 

 organism. 



The results showed that immunization in guinea pigs with killed micro- 

 organisms does not bring about an increase in resistance to the virus. The 

 animals so inoculated appeared tc be even more susceptible to infection than 



