larity. Lashing movements are common in drawn blood. Highly motile end portion absent. Stain with the common aniline dyes; violet with Giemsa's stain. Gram-negative. Growth occurs in ascitic or hydrocoel fluid to which a piece of sterile rabbit kidney is added. Bile salts (10 per cent) : Disintegration of cells is complete. Saponin (10 per cent) : Cells are immo- bilized in 30 minutes, then broken up in a few hours. In some cases a skeletal struc- ture remains. Optimum pH, between 7.2 and 7.4. Serum does not agglutinate Borrelia dut- tonii. Disease in experimental animals (small rodents after monkey passage) is mild. Transmission, accidental and experi- mental, is by conjunctival sac and skin abrasions. Arthropod vector is the louse (Pediculus humanns subsp. humanus), which exhibits normal transmission from the 16th to the 28th day. Found in ticks but not trans- mitted by them. No evidence of hereditary transmission in the louse. Habitat : Found as the cause of epidemic relapsing fever. Transmissible to man and monkeys and from monkej's to mice and rats. 3. Borrelia berbera (Sergent and Foley, 1910) Bergey et al., 1925. (Spirochaeta ber- bera Sergent and Foley, Ann. Inst. Past., S4, 1910, 337; Bergey et al.. Manual, 2nd ed., 1925, 435.) ber'be.ra. M.L. adj. berberus pertaining to the Berbers; named for the Berbers, a North African tribe. Cells are more tenuous than those of other relapsing-fever organisms, measuring 0.2 to 0.3 by 12 to 24 microns. There is no record of cultivation. Antigenically distinct from Borrelia re- cur rentis. Pathogenicity: Virulent for monkej's; produces non-fatal infection in rats and mice. Possibly carried by the louse (Pedicuhis humanus subsp. humanus). Comment: Regarded by some investi- gators as identical with Borrelia recurrentis Bergey et al. Source: From cases of relapsing fever in Algiers, Tunis and Tripoli. Habitat: Found as a cause of relapsing fever in North Africa. 4. Borrelia carteri (Mackie, 1907) Ber- gey et al., 1925. {Spirochaeta carteri Mackie, Ann. Trop. Med. and Parasitol., 1, 1907, 157; also see Indian Med. Gazette, U, 1908, 370; Bergey et al.. Manual, 2nd ed., 1925, 435.) car'te.ri. M.L. gen. noun carteri of Carter; named for R. M. Carter, who, in 1879, de- scribed this organism in the blood of pa- tients with Indian relapsing fever. Morphologically similar to Borrelia ber- bera. Cultivation not recorded. Immunologically, this is probably a dis- tinct species. A succession of distinct ser- ological types occurs with the relapse in a single infection (Cunningham et al., Far Eastern Association of Tropical Medicine, Tokyo, 1925; also see Indian Journal of Medical Research, B2, 1934-1935, 105 and 595; and ibid., 24, 1937, 571 and 581). Carried by Pediculus humanus subsp. humanus. Transmissible to monkeys, rabbits, rats and mice. Comment: Regarded by some investi- gators as identical with Borrelia recurrentis Bergey et al. Habitat: Found as the cause of Indian relapsing fever. 5. Borrelia hispanica (de Buen, 1926) Steinhaus, 1946. (Spirochaeta hispanica de Buen, Ann. de Parasitol., 4, 1926, 185; Stein- haus, Insect Microbiology, 1946, 453.) hi.spa'ni.ca. L. adj. hispanicus Spanish. Transmitted by Ornithodoros erraticus (large form). Pathogenicity: Pathogenic for small lab- oratory animals, especially the guinea pig. Habitat: Found as a cause of relapsing fever in Spain, Portugal and northwest Africa. 6. Borrelia hcrnisii (Davis, 1942) Stein-
