188 EXPEEIMENT STATION EECORD. 



of cows in which tuberculosis! could not be recognized by clinical symptoms, although 

 the animals reacted to the disease. The experiments involved the selection of 10 

 cows all of which reacted to tuberculin, inoculation and feeding experiments with 

 the milk of these cows, and subsequent post-mortem examination of all of the cows. 

 Microscopic examinat^'on and inoculation experiments with the milk in guinea pigs 

 failed to show a single instance in which tubercle bacilli were present. A number of 

 inoculation experiments were made on guinea pigs, but none of the animals devel- 

 oped any symptoms of the disease or showed evidence of being infected when a micro- 

 scopic examination wa^ made post-mortem. Feeding experiments with the milk of 

 these cows were undertaken upon guinea pigs, pigs, and calves. The general result 

 of the feeding experiments substantiated that which was previously obtained by the 

 author in similar experiments. It was shown that the milk of cows which simply 

 reacted to tuberculin does not contain tubercle bacilli. This was proved by micro- 

 scopic examination and by inoculation and feeding experiments with guinea pigs. 

 Further proof was obtained by feeding calves and pigs. In these experiments it was 

 found that calves and pigs could be fed for weeks or even months upon the milk of 

 such cows without becoming infected. The author recognizes that for the ])revention 

 of further spread of tuberculos s the most important measure is the extermination of 

 mammary tuberculosis and cases which may be recognized ly external symptoms. 



Influence of antituberculous serum on the virulence of the tubercle bacillus, 

 F. Akloix(; [Cornpt. Rend. So<: B'loJ. J'urls, .i.l {1901), Xo. ^''}, p}>. 7Sl-7So).— Two 

 series of experiments were conducted on guinea pigs and rabbits. Guinea pigs which 

 were inoculated hypodermically with 2 drops of an emulsion of tubercle bacilli, grown 

 on potato, were killed and examined for the purpose of determining the extent of 

 infection. Other guinea pigs were ino ulated at the same time with 2 drops of 

 enmlsiou of tul)erc-le liacilli in an antitulierculous serum. The development of the 

 disease was more rapid and more extensive in animals which received the antituber- 

 culous serum than in those Avhich were inoculated simply with tubercle bacillus. 

 Similar experiments were made on rabbits with similar results It is concluded that 

 antituberculous serum increases the virulence of the tubercle bacillus and favors the 

 generalization of infection. 



The favoring action of antituberculous serum toward infection by the 

 tubercle bacillus in homogenous liquid cultures, F. Arloing ( Compt. Rend. Soc. 

 Biol. Paris, 53 {1901), No. 84, pp. 950, 951). — Continuing the above work, experiments 

 were made with tubercle bacillus grown on various other media. Rabbits were 

 inoculated w^th a mixture of cultures of tubercle bacillus and an antituberculous 

 serum in the peritoneum. Similar inoculations were made in the pleura of rabbits. 

 All the ral)bits which were inoculated with mixtures of pure cultures and antituber- 

 culous serum showed the development of a generalized infection of tuberculosis. 

 Some of them died and others were killed and examined after death for the purpose 

 of determining the extent of the disease. As a result of post-mortem examinations 

 it was found that the antituberculous serum favored peritoneal infection from pure 

 cultures of tubercle bacillus. It is concluded that this serum increases the virulence 

 of the tubercle bacillus, whether inoculated intrai)eritoneally or hypodermically. 



The value and significance of the Arloing-Courmont serum reaction, 

 especially in reference to the early recognition of tuberculosis, j\I. Beck 

 and Lydia Eabinowitsch {Ztschr. Ili/g. ". Infectionskrank., 87 {1901), No. 2, p>p. 205- 

 224). — Since 1898 a number of articles have been published by Arloing and Cour- 

 mont in whit^h experiments were reported indicating that cultures of the tubercle 

 bacillus could be brought to agglutination by means of the blood serum of tubercu- 

 ous animals. The authors undertook an investigation of this subject and the results 

 of their studies are reported in detail in tabular form. The experimental animals 

 included 78 cattle, of w^hich 19 were nontuberculous. Among the 19 healthy cattle 

 the serum reaction was negative in only 1 case; in 2 cases it appeared to develop in 



