192 STRONG. 



for kiiidlv earryiii;;- out these iiioeiilatioiis. Tlie ileiails of (lie experi- 

 ments are as follows : 



EXPERIMENTS ON IMMUNIZED BATS REINOCULATED WITH "sPJlilLI.UM 

 OARTEEl" OF INDIAN RErjAPSING FEVEE. 



Rat No. l, inuniinized against Koch's African spiroclueta. 



Rat No. 2, immunized against American spirocliseta. 



Rat No. 3. innminized against European spiroclueta. 



Rat No. 4, inimunized against Diitton's African spiroelueta. 



Mouse No. 5, iinimniized against Koch's African spirocha-ta. 



Rat No. 6, nonimnnuie {Mks Railus, Bombay). 



Rat No. 7, nonimmune {Mus Raltus, Bombay). 



Monlvey, nonimmune (Macacus Sinicus). 



The material witli wliicli the animals were inoculated was obtained from a 

 monkey (Macacus (b'i«icM,s) , No. 85, whose blood contained many active spirilla 

 and which was at the height or just before the height of the attack (thirty-six 

 hours before crisis). An equal quantity (about 0.4 cubic centimeter of pure 

 blood) of this citrated blood was injected into animals Nos. 1, 2, 3, and 4. 

 No. 5 received 0.2.5 cubic centimeter pure blood. Nos. 6 and 7 received 0.35 and 

 0.4, respectively, of pure blood. All the injections were made intraperitoneally. 



Results (twenty-four hours after injection) : 



Rat No. 1, 3 spirilla found in twenty minutes' search. 



Rat No. 2, none seen in forty minutes' search. 



Rat No. 3, none seen in thirty minutes' search. 



Rat No. 4, 4 siiirilla seen in twenty minutes' search. 



Mouse No. 5, 25 seen in five minutes' search. 



Rat No. 6 (first control), f) spirilla seen in fifteen minutes' search. 



Rat No. 7 (second control), 7 spirilla seen in five minutes' search. 



Monkey, no spirilla seen. 

 Results (forty-eight hours after injection) : 



Rat No. 1, none in twenty minutes' search. 



Rat No. 2, none in fifteen minutes' search. 



Rat No. 3, none in fifteen minutes' search. 



Rat No. 4, none in ten minutes' search. 



Mouse No. 5, 25 seen in ten minutes' search. 



Rat No. 6, none in ten minutes' search. 



Rat No. 7, 8 seen in fifteen minutes' search. 



Monkey, 1 spirillum seen to a field. 

 Results (seventy-two hours after injection) : 



Blood of rodents all negative after ten, fifteen, oi- (wenty minutes' search. 



Monkey, 3 or 4 spirilla seen to a field. Animal went through a typical attack 

 of the disease. 



On the two subsequent days no spirilla were found in any of the rodents, and 

 no spirilla have since reappeared. 



These experiments seem to show that Bombay spiiillum fever is distinct 

 from African tick fever, but that it constitutes a form of relapsing fever 

 very closely related, if not identical, with the forms .of relapsing fever 

 encountered in Europe and the United States. If anyone wishes to 

 repeat these experiments I must warn him that he will l)e unable to 

 obtain any white mice after leaving Euro])e. Neither in the laboratories 

 of Africa nor of India was I able to obtain these animals. 



