;^48 piroplasma 15igeminum and anaplasma centrale. 



Experiment i. 



Shorthcrn heifer 4120 was inoculated subcutaneously on 

 2/4/18 with 5 c.c. citrated blood (90 blood to 10 of 10 per cent, 

 sodium citrate solution) of heifer 3S30, used for redwater and 

 anaplasmosis vaccine production. Some of the blood was sent 

 by rail to Pietermaritzburg and returned from there, the journey 

 occupying 120 hours or 5 days. 5 c.c. of the returned blood was 

 inoculated into heifer 41 19 on 7/4/18, 4120 therefore acting as 

 control. 



Heifer 4120 showetl P. bigeminum in the blood from the 

 9th to 17th days after inoculation, with a strong temperature 

 reaction and Aiva[)lasma eentrale from 39th to 44th day after 

 inoculation. 



Heifer 41 19 did not show a reaction to redwater, but did to 

 A. ceyitrale from the 36th to 44th day after inoculation. In order 

 to see whether a reaction to redwater had occurred unnoticed, the 

 heifer was bled into citrate solution on 29/4/18, and heifer 41 17 

 was inoculated with 5 c.c. of the blood subcutaneously. 



Heifer 41 17 did not react to redwater, but did to A. eentrale 

 from the 36th t<T 44th day after inoculation. Both heifers 41 19 

 and 41 17, when subsequently inoculated subcutaneously with 5 

 c.c. each of blood of heifer 4120, a reactor to both redwater and 

 anaplasmosis, reacted to redwater only. 



Heifer 41 19 showed a reaction to P. bigeminum on the nth 

 and 1 2th days after inoculation. 



Heifer 411/. Reacted to P. hiycminum from the 7th to 12th 

 days, accompanied by a slight Ijreakdown in immunity to A. een- 

 trale. 



In this experiment one is entitled to conclude that the P. 

 bigemiinum did not survive the sojourn of 120 hours in citrated 

 blood, but that A. eentrale did, and its virulence did not seem to 

 have been in any way reduced. 



This experiment having been concluded, an attempt was 

 made to see whether the approximate survival period of P. 

 bigeminum in citrated blood cculd be found. Blood was again 

 taken into citrate solution (90 parts blood to 10 of 10 per cent, 

 sodium citrate) from a heifer used for redwater and anaplas- 

 mosis vaccine production. Some of this was inoculated imme- 

 diately into susceptible cattle; some was kept foi" 24, 72, and 90 

 hour periods, being sent by post to various places, so as to as 

 closely as possible simulate the vaccine as used by a stock 

 owner. 



Experiment 2. 



Heifer 4118. Inoculated subcutaneously on 22/5/18 with 

 5 c.c. of citrated blood of heifer 3831, which had been kept 24 

 hours. She reacted to P. bigeminum on 21st and 22nd days 

 after inoculation, the reaction being a very weak one. and to A. 

 eentrale from the 41st to 56th days. 



