Transmission of East Coast Fever by Ticks. 
323 
respectively, in order to test their infectivity {vide Experiment No. 1 " C," 
Nos 23 and 24). 
8. Ox 1040 was infested on June 27, 1910, with brown nymphae off 
Cattle 700, 917, and 923 (Eef. Nos. 309, 335, and 268), as above. Ox 1040 
developed East Coast Fever after an incubation time of 13 days, and died 
on the 15th day of illness (July 25, 1910). The blood showed a strong 
infection of Th. parva, but plasma bodies were found in rare numbers only 
in the glands. 
Note. — The nymphae engorged in due time, and moulted into adults by 
September 19, 1910 ; they were used for the infestation of Heifer 1088 
and Calf 1145 {vide Experiment No. 1 " C," Nos. 23 and 24). 
EXPERIMENT No. 1 [continued). 
B." TO DEMONSTRATE THE FACT THAT BROWN TICK IMAGINES, WHICH 
AS LARViE HAD BECOME INFECTED WITH EAST COAST FEVER, 
AFTER HAVING PASSED THEIR NYMPHAL STAGE ON CATTLE 
RENDERED IMMUNE TO EAST COAST FEVER BY INOCULATION, 
NO LONGER TRANSMIT THE DISEASE TO SUSCEPTIBLE CATTLE. 
{e) Ehipicephalus appendiculatus (Ref. Nos. 309, 268, and 335), 
(See previous sub-head (d).) 
Note.— The animals referred to later (Nos. 829, 883, 836, 895, 1047, 
1033, 871, 621, 679, and 615) had all been rendered immune to East Coast 
Fever by inoculation, details of which were given in the Annual Report of 
the Government Veterinary Bacteriologist for 1909-10, under the title 
of " The Artificial Transmission of East Coast Fever " (see pp. 1-55). 
9. Ox 829 was rendered immune to East Coast Fever by inoculation 
(see above). 
Infested on March 24, 1910, with brown nymphge off Calf 700 (Ref. 
No. 309). 
Note. — The engorged nymphae were collected on March 30, 1910 ; they 
moulted into adults on April 21, 1910, and were placed on Heifers 1057 
and 1058 on August 5, 1910, in order to test their infectivity (vide 
Experiment No. 1 " C," Nos. 25 and 26). 
10. Heifer 883 was rendered immune by inoculation {vide above). 
Infested on March 24, 1910, with brown nymphae off Calf 700 (Ref. 
No. 309). 
22 
