450 Chapter XIV 



given birth but also to those they had merely nourished with their milk. 

 This observation proved, to demonstration, that the antitoxins are 

 absorbed by the alimentary canal, a very important fact from several 

 points of view. Later researches have shown that only very young 

 mice are capable of assimilating antitoxin through the intestinal wall. 

 Adult mice, fed by Ehrlich with quantities of antitoxic milk, acquired 

 neither immunity nor any antitoxic property of the blood. Later, 

 Vaillard (Z. c.) was able to show that even the young of other species 

 of animals such as the guinea-pig and the rabbit are incapable of 

 appropriating the antitoxins from milk by the alimentary canal. He 

 repeated Ehrlich's experiments with new-born guinea-pigs and rabbits 

 which he caused to be suckled by mothers vaccinated against tetanus. 

 These young rodents, so treated, were found to possess no immunity 

 whatever ; they were not able, therefore, to absorb the antitoxin 

 [472] found in the milk of their nurses. Remlinger {I, c.) made similar 

 experiments with young guinea-pigs and rabbits suckled by foster 

 mothers which had been vaccinated against the coccobacillus of 

 typhoid fever. As in Vaillard's experiments, the result was negative, 

 the milk of the foster mother did not communicate any refractory 

 condition to the nurselings. Remlinger drew the same conclusion 

 from his researches on the transmission of the agglutinative property 

 of the body fluids. When female rabbits and guinea-pigs are vac- 

 cinated during gestation the young ones acquire, along with the 

 immunity against the typhoid coccobacillus, a certain agglutinative 

 power of the blood serum. When, however, these vaccinated females 

 suckle the progeny of non-vaccinated mothers the agglutinative 

 power of the milk of the foster mother never passes into the blood of 

 the nurselings. Some years before this, Widal and Sicard^ had 

 demonstrated the same fact that young rabbits and new-born kittens, 

 when fed with agglutinative milk, acquired no power of agglutinating 

 the typhoid coccobacillus. They agreed with Ehrlich, however, that 

 the blood serum of young mice fed with agglutinative milk acquired 

 the power of agglutinating the typhoid micro-organism. 



As it was important to determine whether the human subject was 

 capable of acquiring a certain immunity by absorbing antibodies 

 contained in the milk, the study of this question was taken up, 

 especially from the point of view of agglutinative power. Although 

 the relations of this agglutinative power with immunity are very 

 problematical it would be interesting, bearing in mind the analogy 

 ^ Compt. rend. Soc. de bioL, Paris, 1897, p. 804, 



