TULAREMIA AND BACTERIUM TULARIN SE 449 
and isolate colonies in pure culture. Blood, collected aseptically, 
should be plated out on agar. From the pure colonies inoculate 3 
per cent salt agar and examine after twenty-four hours for involution 
forms; make the "stalactite" test in broth containing a few drops of 
neutral oil. (The culture must be kept in an absolutely quiet environ- 
ment to obtain stalactite growth.) This reaction is not absolutely 
distinctive, for other members of the Hemorrhagic Septicemia Group 
may also develop in this manner. 
AnimaJ Inoculation.^X small amount of culture inoculated at the 
root of the tail of a rat subcutaneously or intranasally in a guinea- 
pig will cause death within three to five days with characteristic 
lesions. The organism may be recovered from the internal organs 
and the heart blood. An emulsion of infected material containing 
plague bacilli may be rubbed upon the freshly sha\ed abdomen of a 
guinea-pig with a glass rod. The plague bacillus will enter the under- 
lying tissues and set up a plague infection from which B. pestis will be 
recovered readily in pure culture postmortem. ^ 
TULAREMIA AND BACTERroM TULAR^NSE. 
Tularemia- (Deer Fly Fever, Pahvant Valley Plague^) is a specific 
infectious disease, incited by Bacterium tularsense,'* transmitted from 
rodents to man by the bite of an infested, blood-sucking insect, or by 
handling infected rodents. There seems to be no evidence at present 
that the disease is contagious from man to man. The onset is abrupt, 
with pains and fever. The patient is greatly prostrated. The fever 
is of the septic type, and there is enlargement of the regional lymph 
glands, which are tender and frequently suppurate. Convalescence is 
usually slow. The disease runs its course in from two to six weeks. 
Conjunctivitis is not at all uncommon.'^ 
The disease occurs in wild rabbits and ground squirrels (Citellus 
mollis). Spontaneous infections in these animals, especially rabbits, 
have been reported from Utah, Washington, D. C^ and Cincinnati,^ as 
well as several states mostly south of Mason and Dixon's line. It 
seems to be fairly widespread among these rodents. 
The organism, first isolated and described by McCoy and Chapin, 
is an aerobic, facultatively anaerobic small, ovoid bacillus, measuring 
approximately 0.2 to 0.3 micron in diameter, and about 0.4 to 0.7 
micron in length. It seems to have a delicate capsule, especially when 
1 Albrecht and Ghon: Centralbl. f. Bakteriol., 1899, 26, .362; Kolle: Ztschr. f. Hyg., 
1901, 36, 397. 
- Francis: Public Health Reports, 1921, 36, 1731. 
3 Francis: Ibid., 1919, 34, 2061. 
^ MoCoy and Chapin: .Jour. Infec. Dis., 1912, 10, 61. 
5 Vail: Ophthalmol. Rec, 1914, 23, 487. Sattler: Arch. Ophthaniol., 191.5, 44, 26.5. 
Lamb: Ophthalmol. Rec, 1917, 26, 221. Ledingham and Fraser: Quart. Jour. Med., 
1924, p. 365. Freese: Public Health Reports, 1926, 41, 369. 
6 Francis: Public Health Reports, 1923, 38, 1391. 
' Wherry and Lamb: Jour. Infec. Dis., 1914, 15, 331. 
29 
