350 PIROPLASMA IJIGEMINUM AND ANAPLASMA CENTRALE. 



in smears taken on that day. A mild reaction to A. ccntrale 

 took place from the 27th to 35th days. When subsequently 

 inoculated with 5 c.c. citrated bkod of heifer 4390 (virulent 

 redwater strain) this l)u!l reacted strongly to redwater on 14th 

 to i6th days, and was given trypan blue. These experiments 

 would seem to show that if any reaction at all occurred in heifer 

 4155, it must have been an exceedingly mild one. 



Experiment 5. 



In conjunction with Experiment 3, and using the same 

 controls, heifer 4158 was inoculated with 5 c.c. citrated blood 

 of heifer 3830, which had been kept 90 hours. 



Heifer 4158. Did not react to redwater, but did to A. 

 centrale from the 30th to 45th days. When subsequently inocu- 

 lated with 5 c.c. citrated blood of heifer 3830, inoculated within 

 an hour of taking, a rcactioit to P. bigeminmn occurred en 13th 

 day, and no further reactions took place. 



Although unsatisfactory, the evidence obtained would point 

 towards the survival period of P. bigcmintim in citrated blood 

 being less than 90 hours. In one case it survived 24 hours, and 

 in another it did not. It was therefore decided to repeat the 

 experiments at the first favourable op[)ortunity. 



Experiment (>. 



In October. 19 18. four impcjrtefl bulls were again available 

 for experiments, their numbers being 4410, 4411, 4412, and 4413. 

 Blood from a heifer, 4120, immune to redwater and anaplas- 

 mosis (see Experiment i), was taken into water containing 

 3.8 per cent, of sodium citrate and 2.8 per cent, of saccharose, in 

 the proportion of 90 of blood to 10 of the mixture. Both these 

 solutions, to which the blood was added, were i.sotonic for 

 blood. Bulls 4412 and 4413 were inoculated subcutaneously,, 

 each with 5 c.c. of this blood, bull 4410 with 5 c.c. kept 48 hours, 

 and bull 4411 with 5 c.c. kept 96 hours. 



Bull 4410. No redwater reaction occurred, but one did to 

 A. centrale from 40th to 48th day. Subsequently, when inocu- 

 lated with 5 c.c. blood of heifer 4390 (virulent redwater strain), 

 a marked temperature reaction occurred on the i6th day after 

 moculation, but P. bigeminum could not be found in smears of 

 the blood, though A. centrale was present in small numbers, 

 probably due to a breakdown in immunity to anaplasmosis. 

 Whether a reaction occurred in the first inoculation or not, it is 

 therefore impossible to say, but temperatures could not be taken 

 for a week from the 3rd to lOth day after inoculation, owing to 

 the complete disorganization caused by the influenza epidemic. 



Bull 441 1 did not react to redwater or anaplasmosis, so was 

 subsequently reinoculated with blood of heifer 41 17 (see Experi- 

 ment i), immune to redwater and anaplasmosis. A reaction 

 occurretl to redwater from the 9th to i ith day, and subsequently, 

 on 56th and 63rd days, a mild reaction to A. centrale. 



