122 THE ANIMAL PARASITES OK MAN 



S. recurrent is is the cause of European relapsing fever, and a 

 number of possible varieties of it are associated with relapsing fevers 

 in other parts of the world. Such spirochaetes only differ by bio- 

 logical reactions, such as acquired immunity tests. They include : 



5. rossii, the agent of East African relapsing fever ; S. novyi, the 

 agent of North American relapsing fever; S. carteri, the agent of 

 Indian relapsing fever; S. berbera, the agent of North African and 

 Egyptian relapsing fever. 



OTHER HUMAN SPIROCH^TES are: 



S. schaudinni. This organism, according to Prowazek, is the 

 agent of ulcus tropicum. It varies in length from 10/1, to 20 //,. 



S. aboriginalis has been found in cases of granuloma inguinal e 

 in British New Guinea and Western Australia. It also occurs in 

 dogs, and may not be truly parasitic. 



S. vincenti. This spirochaete is 12 //, to 25 //, in length, tapers at 

 both ends and has few coils. It has been associated with angina 

 vincenti. It often occurs in company with fusiform bacilli. 



S. bronchialis, found by Castellani in 1907 in cases of bronchitis 

 in Ceylon. The parasites are delicate, but show morphological 

 variation. This organism is important and has since been found 

 in the West Indies, India, Philippine Islands and various parts of 

 Africa, such as the Anglo-Egyptian Sudan, Uganda and West Africa. 

 It has recently been the subject of research by Chalmers and 

 O'Farrell, Taylor, and Fantham. 



S. phagedenis was found by Noguchi in a ten days old ulcerated 

 swelling of the labium. The organism shows much variation in size, 

 being 4/4 to 30 //, in length. 



S, refringens (Schaudinn, 1905) occurs in association with 

 Treponema pallidum in syphilitic lesions, but is non-pathogenic. It 

 is 20 /x to 35 /A long and 0*5 JJL to 0*75 //, broad, being larger than 

 T. pallidum and more easily stained. 



Various spirochsetes have also been notified in vomits, chiefly in 

 Australia ; others from the human intestinal tract, e.g., S. eurygyrata ," 

 S. stenogyrata (Werner) ; S. hachaizce (Kowalski), in cholera motions; 

 S. buccalis (Cohn, 1875) and S. dentium occurring in the human 

 mouth and in carious teeth (S. dentium, Koch, 1877, being the 

 smaller) ; S. acuminata and S. obtusa found by Castellani in open 

 sores in cases of yaws. 



Animal spirochaetes of economic importance include : 



S. anserina, highly pathogenic to geese. 



S. gallinarum ( = S. marchoitxi) in fowls. (See p. 119.) 



S. theileri in cattle and S. ovina in sheep also occur in Africa; 

 their pathogenicity is not clear. 



S. laverani ( = S. muris), occurring in the blood of and patho- 



