Genus I. Bon-elia Swellengrehel, 1907. (Swellengrebel, Ann. Inst. Past., £1 , 1907 (June), 582; Spiruschniidinnia Suml)on, in Man- son, Tropical Diseases, 1907 (August), 833; Spironema Bergey et al., Manual, 1st ed., 1923, 424; not Spironema Vuillemin, Compt. rend. Acad. Sci., Paris, I40, 1905, 1567.) Bor.rel'i.a. M.L. fem.gen.n. Borrelia of Borrel; named for A. Borrel, a French scientist. Cells, 8 to 16 microns in length, with coarse, shallow, irregular spirals, a few of which may be obtuse-angled. Generally taper terminally into fine filaments. Stain easily with ordinary aniline dyes. Refractive inde.x approximately the same as that of true bacteria. Parasitic upon many forms of animal life. Some are pathogenic for man, other mammals or birds. Generally these organisms are hematophytic or are found on mucous membranes. Some are transmitted by the bites of arthropods. The type species is Borrelia anserina (Sakharoff) Bergey et al. Key to the species of genus Borrelia. I. From birds. 1. Borrelia anserina. II. From animals other than birds. A. From man. 1. Cause relapsing fever in man. a. Transmitted bj' arthropod vectors. b. Arthropod vector is the louse Pediculus humaniis subsp. humanus. 2. Borrelia recurrentis. 3. Borrelia berbera. 4. Borrelia carteri. bb. Arthropod vector is of the genus Ornithodoros (tick). c'. Transmitted by Ornithodoros erraticus (large form). 5. Borrelia hispanica. c'. Transmitted by Ornithodoros hermsi. 6. Borrelia hermsii. c^. Transmitted by Ornithodoros mouhata. 7. Borrelia duttonii. c*. Transmitted by Ornithodoros parkeri. 8. Borrelia parkeri. c^. Transmitted by Ornithodoros rudis. 9. Borrelia venezuelensis. c^. Transmitted by Ornithodoros tholozani. 10. Borrelia persica. c^. Transmitted by Ornithodoros turicata. 11. Borrelia turicatae. c^. Transmitted by Ornithodoros verrucosus. 12. Borrelia caucasica. aa. Arthropod vector unknown. 13. Borrelia novyi. 14. Borrelia kochii. 2. Do not cause relapsing fever in man. a. From the mouth and from the respiratory mucous membrane. 15. Borrelia buccalis. 16. Borrelia vincentii. aa. From the genital mucous membranes. 17. Borrelia refringens. ]'. From animals other than man.
