DIAGNOSIS OF AFKICAN TICK FEVER, 



241 



Remarks. — The precipitin experiments performed in duplicate and in 

 dilutions of the different sera of 1 to 5 and 1 to 10 were all negative. 

 However, it is to be noted that agglutinins had already developed in 

 some of the sera. 



On November 11 the following further agglutinative reactions were performed 

 with the same sera of animals numbered 1 and 2, and 5, (3 and 7 ; the citrated 

 blood of mice numbered 10 and 11, infected with spirochete on November 8, 

 being used to furnish the spirochetal which were numerous and very active at 

 the time of the test: 



Num- 

 ber. 



Conditions of reaction. 



Agglutination. 



Sera of— 



Plus citrated blood of— 



I 



II 

 III 

 IV 



Mice 1 and 2 (immune to 

 African S) . 



Mice 5, 6, 7 (immune to 

 American ti) . 



Mice 5, 6, 7 (immune to 

 American .5) . 



Mice 1 and 2 (immune to 

 African ,S'). 



Mouse 10 (infected 

 with African S). 



_ _ do 



Positive good clumps and star forms 

 in 5 to 10 minutes in dilutions of 

 1-10 and 1-20. Parasites have lost 

 almost entirely their motility. 



Negative. Parasites retain their 

 motility and remain singly. No 

 clumps or agglutination in dilu- 

 tions of 1-5, 1-10. 



Positive. Very large clumps and 

 balls of organisms in 5 minutes. 

 Marked reactions in dilutions of 

 1-10 and 1-20. 



Negative. Organisms remain sin- 

 gle even in dilutions 1-2 and 1-10; 

 also still motile. 



Mouse 11 (infected 

 with American 5) . 



do 





Remarks. — The above reactions were observed in moist preparations 

 and were confirmed also by stained ones. In experiments I and III, 

 in the dilution 1 to 2, the agglutination was not so visibly marked because 

 of the spirolytic action of the sera on the spirochastaa. 



SERIES NO. IV. 



Experiments with the African spirocha'ta. — November 15, rat number 1 which 

 had received two previous injections with African spirochete on October 4 and 

 November 8 was again inoculated November 15 with blood containing numerous 

 African spirochete. 



Rat number 2, which had been given one previous injection of the African 

 spirocheta on November 8, was again inoculated November 15 in the same manner 

 as rat number 1. 



Rat number 3, which had not been previously injected witli spirochete, was 

 also inoculated on November 15 in the same manner as rats numbered 1 and 2. 



Experiments with the American spirocha'ta. — Rat number 4, which had received 

 two previous injections with American spirochete on October 4 and November S, 

 was again inoculated on November 15 with blood containing numerous American 

 spirochete. 



Rat number 5, which had been given one previous injection with the American 

 spirocheta on November 8, was again inoculated on November 15 in the same 

 manner as rat number 4. 



Rat number 6, which had not previously been inoculated with spirochtete, was 

 also injected on November 15 in the same manner as rat number 4. 



