84 EXPERIMENT STATION RECORD. [Vol.43 



to transmil the disease in the followiiifi stajies. The multiiilicatiou of the 

 parasite tal<es phice more particularly in the capillaries of the brain and to a 

 less extent in the kidneys and l)ont^ marrow. 



Transmission of canine piroplasmosis in Tunis by Rbipicephalus san- 

 Suineus, E. r.i{TMi'T (Bui. Sov. I'ath. JJxot.. 12 il'JJ'J), Xo. 10. pp. 757-764, fig. 

 1). — Canine piroplasmosis in Tunis is transmitted by R. satiguineiis adults 

 which are the otTspring of females that enjiorjied on affected animals. The 

 larvjB and nymphs from such infecttni females do not transmit the infection, 

 but become pathogenic as soon as they become adults. Nymphs which have 

 fed upon virulent blood do not transmit the disease when they become adults. 

 It is pointed out that the affection Is transmitted by three species, namely. 

 Haunt phjisoUs leochi, R. sanguineus, and Dermacentor reticulatus. A number 

 of nymphs of l.vodcs ricinus and H. concinna obtained from females which had 

 fed upon a sick dog did not transmit the disease. 



[Fowl typhoid in France], F. D'Hekelle {('omitt. Rend. Acad. Svi. [Paris], 

 169 (1919), Nos. IS, pp. 817-819; 20. pp. 932-934; abs. in Vet. Rev., 4 {1920), 

 A'o. 1, pp. 56, 57). — Two papers are presented. 



I. An epidemic of fov^l typhoid (pp. 817-819).— This paper describes a 

 serious and extensive outbreak of fowl typhoid. In France originating In the 

 spring of 1916. From samples of the blood of 67 fowls which had succumbed 

 to the disease Bacterium sanguinariUm was isolated in 56 cases. In the re- 

 maining cases the blood was aseptic. 



II. The r6le of the hacterioptiagoui^ mierohe in fowl typhoid (pp. 932-934). — 

 In connection with the outbreak of fowl typhoid noted above, the author has 

 made observations which confirm his theory concerning the role of bacterlo- 

 phagous microorganisms In the control of infectious diseases. He states that 

 in the feces of fowls, as of all vertebrates, it Is possible to demonstrate the 

 presence of a filterable bacteriophagous organism which is the normal inhabi- 

 tant of the Intestine, and which is thought to bear the same relation to the 

 pathogenic organism that the latter bears to the body of the vertebrate. 

 Against a particular microorganism, as for example B. sanguinarium, the 

 bacteriophage, which is first avirulent, becomes Increasingly virulent with 

 the ingestion of the pathogen by the host until a point may be reached at 

 which the pathogen is destroyed. The transmission of bacteriophages with 

 heightened virulence results in the sudden arrest of an outbreak of the dis- 

 ease. In other words, Immunity to the disease is contagious as well as the 

 disease itself. 



The author states that immunization experiments based upon this principle 

 are in progress in connection with the fowl typhod epidemic, and are meeting 

 with success. 



The bacteriophagous microorganism, F. D'Herelle '(Compt. Rend. Soc. 

 Biol. [Paris]. 82 (1919), No. 30. pp. 1237-12.39).— A further discussion of the 

 author's theory notiMl above. 



Botulism in chickens, G. H. Hart (Jour. Amcr. Vet. Med. /Is.soc, 57 (1920), 

 No. 1, pp. 75-77, figs. 2). — An outbreak of botulism or limberneck in a flock of 

 800 fowls In Santa Clara County, Cal., resulting In the death of 643 of the 

 fowls, Is reported. The Infection was traced to home-canned string beans 

 which on account of a bad odor had been consigned to the garbage and later 

 fed the hens. 



This outbreak emphasizes the necessity of destroying all spoiled canned 

 goods, or of thoroughly boiling them to destroy the toxin of Bacillus botulinus 

 before feeding to poultry or other animals. 



