1917] VETERINARY MEDICINE. 81 



such preparations from rabid brains, but that true Negri bodies are only present 

 in the central nervous tissue of animals which were suffering from rabies at 

 the time of their death. 



Experimental epidemiology in tuberculosis, A. Distaso (Jour. Infect. Dis- 

 eases, 19 (1916), No. 4, PP- 62S-6S7). — Experiments are reported from which the 

 author concludes that guinea pigs can become infected through contact. The 

 infectivity follows a curve which is nil at the beginning of the infection, in- 

 creases gradually to the highest point, and is afterward no longer dangerous. 



" It seems that at the beginning of the process few tubercle bacilli are ex- 

 creted, with which the new contact can easily deal and acquire a kind of resist- 

 ance which preserves the animal when the excretion is at its acme; but, as 

 soon as the infection goes on and the microbes swarm in the body, then massive 

 doses are excreted. By this time the new contact is powerless to cope at once 

 with this large quantity, and therefore the pathogenic process establishes itself, 

 and this is made worse by the daily absorption of great quantities of virus." 

 This condition arose between the ninth and the thirty-third day after the 

 infection. 



''After this period a puzzling condition was observed. The guinea pigs no 

 longer contracted the disease. It was assumed that at about this time the 

 process of the encapsulation of the lesions began. Up to this time the virus 

 had been wandering in the organism ; after that period the organism had the 

 power to form around the virus a wall which only let through the toxin, and 

 perhaps a few microbes, or none, were excreted. Then the contacts could no 

 longer be infected." 



Some experimental data to substantiate the fact that the channel of infection 

 in tuberculosis in guinea pigs is chiefly through the nose are submitted. 



The relation of the results of the experimental study to the epidemiology of 

 human tuberculosis is indicated. 



A method of producing antigen for complement fixation in tuberculosis, 

 H. R. MiLLEB and H. Zinsser (Proc. N. T. Path. 8oc., n. ser., 16 (1916), No. 1-2, 

 pp. 28-SO). — The authors have prepared an antigen for complement fixation in 

 tuberculosis by grinding a weighed amount of bacillary substance with salt 

 and subsequent suspension in distilled water until isotonicity is obtained. The 

 antigen so prepared is not anticomplementary in quantities as high as 1 cc, 

 and has given positive fixation in quantities as low as 0.02 cc. 



The fate of the mammalian tuberculosis bacillus in sparrows and chickens, 

 L. Van Es and A. F. Schalk (Jour. Infect. Diseases, 19 (1916), No. 4, pp. 614- 

 627). — The authors at the North Dakota Experiment Station have observed 

 that birds (common sparrows and chickens) into which mammalian tuberculosis 

 bacilli are introduced, either by ingestion or by inoculation, die in a highly 

 emaciated state, but are almost entirely free from any gross lesions character- 

 istic of the disease. The birds were found to retain the organisms for long 

 periods with their pathogenic characteristics fully preserved. 



It is indicated from the results that it is possible that birds may serve as 

 Intermediary carriers and transmitters of mammalian tuberculosis. The results 

 confirm in part similar observations made by Auclair * in pigeons. 



Bovine tuberculosis, C. M. Haeinq (California Sta. Circ. 155 (1916), pp. 

 19). — This circular discusses the subject under the general topics of suscepti- 

 bility, symptoms, etiology, modes of infection, methods of detection (intra- 

 dermal, ophthalmic, and subcutaneous tuberculin reactions), Indications for use 

 and limitations of the various methods, and control and suppression of the 

 disease. 



»Arch. M6d. Expt. et Anat. Path. [Paris], 1. sec, 9 (1897), No. 3, pp. 277-281. 



