2. Found in the buffalo. 7. Haemobartonella sturmanii. B. Not found in herbivorous animals. 1. Found in carnivorous animals (dogs). 8. Haemobartonella canis. 2. Found in insectivorous animals (shrews). 9. Haemohartonella blarinae. 1. Haemobartonella imiris (Mayer, 1921) Tyzzer and Weinman, 1939. {Bar- tonella vfiuris Mayer, Arch. f. Schiffs. u. Tropen-Hyg., 25, 1921, 151; Bartonella muris ratti Regendanz and Kikuth, Compt. rend. Soc. Biol., Paris, 98, 1928, 1578; Tyzzer and Weinman, Amer. Jour. Hyg., 30 (B), 1939, 143.) mu'ris. L. noun mus the mouse; L. gen. noun mtiris of the mouse. Slender rods with rounded ends, fre- quently showing granules or swellings at either one or both extremities and dumb- bell, coccoid or diplococcoid forms. Occur singly, in pairs or in short chains of 3 or 4 elements and, when abundant, in parallel groupings. The rods measure 0.1 by 0.7 to 1.3 microns, sometimes as much as half the length of a red blood cell, and the coccoids measure 0.1 to 0.2 micron in diameter. Elec- tron photographs of blood preparations, utilizing enlargements of 7000 X or more, show the rods to be composed of mono- morphic, rounded discs 0.3 to 0.5 micron in diameter; no cell membrane is evident, and the protoplasm appears structureless. No fiagella were demonstrated (Wigand and Peters, Ztschr. f. Tropenmed. u. Parasit., 2, 1950, 206; also see ibid., 3, 1952, 437). These organisms have been reported as occurring on and in erythrocytes and in depressions of the surfaces of the red blood cells as well as in the plasma. There is lack of agreement among investigators regarding the ability to see and to determine the motility of these organisms in the fresh state. Various au- thors report (1) Brownian movement, (2) slow and sinuous motion in the red cell, or (3) rapid motion. Preferred stains are those of the Romanowsky tj'pe. With Giemsa's stain, various investigators report (1) an intense red coloration, (2) a bluish tinge with distinct pink shading, or (3) blue with purple granules. With Wright's stain, the organisms stain bluish with reddish granules at the ends. With Schilling's methylene blue-eosin stain, the organisms stain a bright red color and the erythrocytes stain blue. Stain faintly with Manson's stain, pyronin-methyl green and fuchsin. Gram- negative. Cultivated with difficulty. Divergent re- sults have been published. Growth has been reported on various media (blood agar, agar with 2 per cent defibrinated rat blood, horse blood agar, N. N. N., Blutrosplatte of Weth- mar, hormone agar with blood of rabbit, horse or man, ascitic fluid agar, chocolate agar, semi-solid rabbit serum agar, semi- solid rabbit blood agar, Noguchi-Wenyon medium, defibrinated rat blood, glucose broth, Tarozzi broth, peptone water), but usually growth was scant or could not be continued by transfer to the same medium, or the organism isolated was either non- infectious or the possibility of latent infec- tions in the recipient animal was not ex- cluded. Best results are apparently obtained with semi-solid rabbit- or rat-serum agar and semi-solid rabbit-blood agar. No con- clusive results have been reported in tissue culture; with the chick embryo, the reports are either contradictory or divergent. Filterability: Non-filterable with either the Seitz or the Berkefeld N filter. Immunology: No authentic case of true natural immunity in rats has been estab- lished. Acquired immunity occurs in (1) the latently infected rat, (2) the infected rat after splenectomy and recovery from the disease, the period of resistance correspond- ing to the duration of latency, (3) the non- splenectomized, non-carrier rat following infection, and (4) animals other than the rat following infection. Serology: No precii)itins, thrombocyto- barin, isoagglutinins or cold hemolysins have been reported in the sera of anemic rats. Contradictory results have been ob- tained in the Weil-Felix reaction utilizing
