YELLOW FEVER AND THE LEPTOSPIRA 887 



monkeys, rabbits, rats and guinea-pigs with the blood of patients 

 in July, 1913, and found that the guinea-pigs developed albuminuria, 

 Jaundice and hemorrhages when the blood was injected during the 

 first seven days of the illness. Subsequently, they found the spiro- 

 chaetes in large numbers in the livers of inoculated guinea-pigs, 

 and following this, found them microscopically in six specimens of 

 patients' blood and at autopsies. The jaundice in the guinea-pigs 

 appears about seven or eight days after inoculation, the shortest 

 time being six days and the longest thirteen. The disease can be 

 kept going in guinea-pigs through many generations. Rabbits are 

 insusceptible. Mice and rats seem to be slightly susceptible. 



The organism seems always to remain outside the blood cells 

 and is present in the interstitial tissues of organs. It has irregular 

 wavy curves and is from 6 to 9 micra long, the largest being 12 

 to 13. Thickness seems to vary with staining methods. Undula- 

 tions are more irregular than those of treponema pallidum and are 

 usually composed of two or three large irregular and four or five 

 smaller waves. 



Cultivation was successful in the hands of Inada and his co- 

 workers by the method used by Noguchi in the case of the spiro- 

 chaete of recurrent fever. They used guinea-pig instead of rabbit 

 kidney, and covered their deep tubes with liquid paraffin. They 

 found, however, that 37 C. is not the best temperature for develop- 

 ment, but that the cultures grow best at between 22 and 25 C. 

 The cultures are odorless and there is no coagulation of the 

 fluid which remains clear, even slight cloudiness indicating con- 

 tamination. The cultures may live from three to six weeks in the 

 first generation, and in later generations as long as fifty-five days. 



Transmission. Subsequent to the announcement of Inada 's dis- 

 covery, Miyjajima called attention to the fact that he had seen 

 spirochaetes in the kidneys of field mice. This clue was followed 

 up by Ido, Hoki, Ito, Wani 26 and many others who found spirochaetes 

 similar to the ones described by Inada in house and roof rats, Epymis or 

 Mus alexandrinus and Mus norvegicus. Since that time Stokes 27 demon- 

 strated the organisms in the kidneys of field rats in the neighborhood 

 of infected districts in Flanders, and Noguchi 28 has found similar 



24 Ido, Hoki, Ito, and Wani, Jour. Exper. Med., 26, 1917, 341. 

 27 Stokes, Eyle and Tytler, Lancet, 1, 1917, 142. 

 2S No(/uchi, Jour. Exper. Med., 25, 1917, 755. 



