190 STRONG. 



The published (lescriptioii of Mackie, wlio liad ])l('nly of material at 

 liis disposal for study, also does not lend suj)port to the niorphologicaj 

 diflfevenees which Novy described for the Indian spiroclvtcta. Mackie 

 found the American spirochseta thinner than the Asiatic one. Novy, 

 moreover, conjectured that the Tiulian species possessed diffuse flagella, 

 while Mackie describes the appearance of only a single flagellum in 

 the Indian species, wliicb, howevei', he regards as a collapsed sheath 

 rather than a true fiagellum. l\tackie performed some agglutinating 

 experiments M'ith an agglutinating serum prepai'ed against the American 

 spirochaeta and sent him by Novy. However, the serum failed to 

 agglutinate the Bombay spirochtfita. Whether this was due to the 

 fact that the serum had lost its agglutinating properties after leaving 

 Novy's laboratory, or that a more specific complement might have been 

 necessary than that supplied by the Bombay rat, or to the fact that the 

 Bombay spirochieta was of a different variety, Mackie could not state. 

 I have already called attention to the uncertainty in obtaining the ag- 

 glutination test with these spirochtsetae. In a later article -'■' Mackie has 

 summarized the evidence he was able to collect from the literature and 

 made a comparison of all the strains. 



I therefore determined to try to throw further light upon the question 

 of the nature of Bombay spirillum fever. The various strains of spiro- 

 chaetse — African, American and European — were collected during my 

 travels in the different countries. I desire to thank Professors Prowazek 

 of Hamburg, Flexner of New York, and Dryer of Egypt for supplying 

 me from their respective laboratories with strains of these organisms. 

 As most of you are aware, these spirochaatse can only be kept alive success- 

 fully in the animal body and can not be cultivated in the test tube on 

 artificial media. ^^ White mice are the only animals satisfactorily suscep- 

 tible to all of the species. It was therefore necessary, in order to carry 

 out this work, to travel with a plentiful supply of these animals as well 

 as with a supply of white rats. Moreover, in order to be sure not to 

 lose any of the strains, it was found necessary to inoculate with each 

 strain a fresh mouse with the infected blood of another animal every 

 third or fourth day. There were some difficulties encountered in carrying 

 out these successive inoculations while traveling from continent to con- 

 tinent during a period of four months. In passing, it may be of interest 

 to remark that in Egypt I was able to find and identify several cases of 

 relapsing fever which were caused by the European variety of spirochaetse, 

 as well as a case of African tick fever caused by the Spiroclueta Duttoni. 



=»?/. 7. Med. Jour. (1908), 88, 337. 



""The collodion sac method of cultivation in the abdominal cavity of an animal, 

 as descibed by Levaditi and subsequently by Novy and Knapp, is too uncertain to 

 be always relied upon. 



