91('» EXPERIMENT STATION RECORD. 



I Experiments concerning: tuberculosis, I, M. J)oi{si;r ( l'. S. I)i/>l. Af/r., Bureau 

 of Atihnitl liidiistrii Unl. .',:, pp. :!(), pl.t. .7). — Tlu' i>r(.'St'nt i)art of tluH bulletin is con- 

 cerned with a disJcuHsion of tlie virulence of human and ))ovine tubercle bacilli lor 

 guinea i)igs and ral)l)itH. Tubercle bacilli were ()))tained from cattle as well as from 

 children and adult human beings, and this material was used in the inoculation of 

 guinea ])igs and rabbits for the purpose of testing its virulence. In the isolation and 

 proi)agation of all cultures a medium was used consisting of mixed white and yolk 

 of liens' eggs, and pure cultures were obtained from guinea i)igs inoculated sub- 

 cutaneously with bits of tissue from the various cases of tuberculosis. It was found 

 during the author's numerous exj)eriments that the gross characters of cultures on 

 the egg medium permitted the seitaration of the cultures into 2 groui)s, the lirst of 

 which consisted of 2 bovine and 2 human cultures, while the second incKided only 

 human tubercle bacilli. The niicroscoj)ic characters of various cultures on egg media 

 were not such as to allow the differentiation between human and bovine bacilli. Like- 

 wise no differentiation could be made in cultures on dog serum. The guinea i)igs 

 used in these experiments were healthy and of an average weight of 532 gm. 

 Detailed notes are given on the behavior of various inoculated guinea pigs and the 

 periods during which they lived after inoculation. It was found during these 

 experiments that certain tubercle bacilli of human origin can not be distinguished 

 from the standpoint of their culture, morphology, or virulence for rabbits and 

 guinea })igs from tubercle bacilli of bovine origin. Considerable variation in the 

 virulence of human tubercle bacilli for rabbits and guinea pigs was observed. The 

 general conclusions which are stated as being based on this and other parts of the 

 bulletin still to be iniblished may be stated as follows: From cases of human tuber- 

 culosis bacilli may be obtained which will produce the disease in pigs, cattle, and 

 monkeys when inoculated subcutaneously. The genetic relation of tubercle bacilli 

 of various origins appears to be well established. As a rule, bovine bacilli are more 

 virulent than human bacilli for all animals upon which experiments have l)een 

 made. 



Reports on bovine tuberculosis and public health, D. E. Salmon ( U. S. Dept. 

 A(jr., Biircdii of Aniriial IikJkMi-ij llnJ. f)o, pp. CS). — This bulletin contains 3 reports 

 made before the American Public Health Association in 1901, 1902, and 1903, re- 

 sjiectively. The reports have all been noted (E. S. R., 13, p. 78(5; 15, pp. 313, 512). 



Homogeneous cultures of the human tubercle bacillus in peptonized Avater 

 and the serum reaction obtained with such cultures, E. Hawthokn [Compl. 

 Rend. Soc. Biol. Pari.% 55 {1903), No. 22, pp. 816, 817).— The author describes the 

 behavior of the human tubercle bacillus when grown in peptonized water, and notes 

 briefl)^ certain agglutination experiments made with organisms thus treated. In the 

 agglutination experiments the method of Arloing was closely followed. The results 

 indicate that considerable dependence may be placed upon the agglutination method 

 in diagnosing tuberculosis. The serum reaction was positive only in the case of 

 animals which were affected with tuberculosis. 



Experiments on tuberculosis, G. Dean and C. Todd {Jour. Path, and Bad., 8 

 {liiOS), No. 4, p]>. 458-4^^9). — The object of the experiments recorded in this paper 

 was to determine whether the human tubercle bacillus undergoes any change in 

 virulence for cattle by a i^reliminary passage through other animals. The experi- 

 mental animals employed were pigs, cats, rabbits, rats, and mice. A considerable 

 number of each sj^ecies was used and the material employed for the inoculation of 

 calves was taken from the experimental animals which first succumVjed to infection. 

 The calves were killed and carefully examined after a period of 4 months. The 

 ex2)eriments wliich are described in detail indicate that the human tubercle bacillus 

 is not greatly increased in virulence for calves l)y a single passage through the pig, 

 cat, rabbit, or rat. The human tubercle bacillus, however, proved to be virulent 

 for calves and capable of producing extensive granular tuberculosis in these animals. 



