23 2 STRONG. 



forms of this type of disease due to different species of spirochaetae, and 

 Ross and .Milne had stated that it was possible there might be more than 

 line variety of tick fever. 



In 1906, Now and Knapp, 7 after a study of a ease of relapsing fever in the 

 United States, concluded that because of morphological characteristics which 

 they were able to detect in stained specimens of the spirochsetae from their own 

 case, and in those of African spirochsetse obtained by them from the Liverpool 

 School of Tropical Medicine, relapsing fever and tick fever are distinct. They 

 also based this claim upon the published experiments of Dutton and Todd 

 and particularly of Breiril and Kinghorn, 8 who found that the spirochseta of the 

 tick variety was frequently fatal to rats and mice and that in rats from three 

 to four relapses occurred before death. Novy and Knapp found that in the case 

 of the spirochseta, which they regarded as Spirillum obermeieri, the infection in 

 rats was shorter and that no relapses occurred. They also believed that the 

 diffuse flagella of the organism of tick fever as pictured by Zettnow • served as 

 an additional •'clinching" proof and effectually differentiated it from Sp. ober- 

 meieri which had, according to their observations, but a single terminal flagellum. 

 However, according to later observers, TJhlenhuth and Hsendel, 10 Novy was not 

 working with Spirochceta obermeieri, but with another species, an American 

 variety. Breinl and Kinghorn " also found that a monkey and several rats 

 immunized against the American spirochseta (supposed to be identical with 

 Sp. obermeieri) remained susceptible to the African species. They were also 

 able to infect a horse, dogs, rabbits, guinea pigs and other animals with the 

 tick-fever parasite. They therefore concluded that the two varieties, American 

 and African relapsing fever, are distinct. Novy and Knapp proposed to dif- 

 ferentiate the different species of spirochetes by serum reactions, specific agglu- 

 tinins and bacteriolysins, as well as by animal inoculations. TJhlenhuth and 

 Haendel and Frankel, 12 during the present year, and very recently Manteufel, 13 

 by means of animal inoculations as well as by agglutinative and bacteriolytic 

 reactions, have found that different results are obtained with the European, 

 African and American spirochaetae, and they regard them as three distinct species. 

 Schellack" has also very recently recounted the morphological differences in 

 the European, American and African spirochsetse of the recurring fevers. 



During a recent visit to the Institut fiir Schiffs- und Tropenkrank- 

 heiten in Hamburg, I had the opportunity, through the kindness of 

 Professor Prowazek, of studying strains of spirochaetae obtained from 

 America and from Africa, and since this time, in different countries, I 

 have examined the other strains of spirochaetae already described in the 

 literature. In the present paper I shall not consider particularly the 

 work in regard to the differentiation of all the spirochaetae of the relapsing 



7 J. Am. Med. Ass. (1906), 46, 116. ./. Infect. Dis. (1900), 3, 291. 

 8 Lancet (1900), March 10, 668. Mem. Liv. School Trop. Med. 20, 61. 

 "Ztschr. f. Hyg. u. Infectionskranl-h. (1906), 52, 539. 

 "• Arb. a. d. I:. Gsndtsamte (1907), 26, Heft I, 1. 



"■Lancet (1906), June 16. 1690. Mem. Liv. School Trop. Med. (1906). 20, 

 61, 69, and 21, 1. 



v 'B,rl. l-lin. Wchnsch. (1907), 44, 681. 



"'Arb. a. d. /.-. Gsndhtsamte (1907). 27, Hefte II, 327. 



"Arb. a. d. 1c. Gsndhtsamte (1907), 27, Hefte II, 364. 



