EXPERIMENT STATION BULLETINS. 613 



pass througli the placenta into the body of the fetus, even if the mother 

 becomes immiine to the disease. However, he says this may occur from 

 pathological changes in the placenta and from the presence of the antigen 

 in the placenta which serves to stimulate the production of antibodies 

 that pass into the circulation of the fetus. In order to throw more light 

 on the statement made by Pfoundler, three pregnant cows were injected 

 subcutaneously and intravenously first with five and ten cubic centi- 

 meters of a killed suspension and then twenty cubic centimeters of a live 

 suspension of Bad. abortus at intervals of ten days during their seventh 

 month of gestation. One of the cows aborted during the eighth month of 

 gestation, one gave birth to a premature living calf and the remaining 

 cow had a normal parturition. The blood sera of the dams reacted 

 strongly to the agglutination and complement fixation tests. The blood 

 sera of two of the calves gave a negative reaction at birth. The blood 

 serum of the premature calf gave a positive reaction. Altho these results 

 are limited, it readily appears that antibodies circulating in the body 

 of the mother are not transmitted to the fetus in utero under normal 

 conditions. Marshall (6) says that it has been shown by means of 

 precipitin reaction, that if egg-albumin is injected into the mother some 

 of it passes unchanged to the fetus. On the other hand, the proteins 

 of ox-serum cannot be recognized in the fetal blood, even when a con- 

 siderable quantity is injected into the mother (rabbit). 



A very interesting occurrence is to be noted in connection with calves 

 that possess antibodies in their blood at birth. In every instance in which 

 the blood of the offspring was positive, the milk of the dam was positive. 

 Furthermore, Bad. abortus was demonstrated present in the milk of the 

 dams by means of guinea pig inoculations. Would this occurrence in- 

 dicate that an infection of the udder travels to the uterus through the 

 blood or lymphatic system? This question cannot be answered at the 

 present writing. 



The results shown in Tables 16 and 17, clearly emphasize the necessity 

 of testing the blood of calves at birth in experiments of this nature. 

 It would not be logical to assume that these calves acquired the positive 

 reactions as a result of ingesting infected milk since the blood sera of the 

 calves were not tested until after they had received milk. This precaution 

 has not been observed in similar researches by others. 



A study of the tables reveals the fact that a larger number of positive 

 reactions was obtained with the complement fixation test than with the 

 agglutination test. In fact, erroneous conclusions would have been 

 drawn from the results had not the complement fixation test been em- 

 ployed in this study. 



The matting and staining of the preputial hairs of bull and heifer 

 calves is a subject to which much importance has been attached by 

 Williams (4) in his investigations. He concludes from his observations 

 that calves fed upon raw milk in almost every instance acquired a mat- 

 ting and staining of the sexual hairs from thirty to sixty days after 

 birth. He further believes that Bad. abortus may be the cause of this 

 phenomenon. 



The observations made in this study do not confirm similar observa- 

 tions made by Williams. In very few instances, has there been a mat- 



