322 Transactions of the Royal Society of South Africa. 
Heifer 1088 and Calf 1145 in order to test their infectivity {vide later 
Experiment No. 1 " C," Nos. 23 and 24). 
4. Heifer 914 was infested on June 28, 1910, with brown nymphae off 
Cattle 700, 917, and 923 (Eef. Nos. 309, 335, and 268), as above. It 
developed East Coast Fever after an incubation time of 13 days and 
recovered. The blood contained Th. parva, and plasma bodies were found 
in the glands. 
Note. — The engorged brown nymphje were all collected by July 12, 
1910, and moulted into adults by September 19, 1910; they were placed 
on Heifer 1088 and Calf 1145 on December 15, 1910, and on January 6, 
1911, respectively, in order to test their infectivity {vide later Experiment 
No. 1 "C," Nos. 23 and 24). 
5. Heifer 1012 was infested on June 27, 1910, with brown nymphae oft 
Cattle 700, 917, and 923 (Kef. Nos. 309, 335, and 268), as above. It 
developed East Coast Fever after an incubation time of 12 days, and died 
on July 26, 1910. The blood was found to contam Th. parva, and plasma 
bodies were noted in the glands. 
Note. — The engorged nymphae were collected in due time, and were 
finally placed on Heifer 1088 and on Calf 1145 in order to test their infec- 
tivity {vide Experiment No. 1 " C," Nos. 23 and 24). 
6. Heifer 1011 was infested on June 27, 1910, with brown nymphae off 
Cattle 700, 917, and 923 (Eef. Nos. 309, 335, and 268), as above. After 
an incubation time of 13 days an East Coast Fever reaction set in, and 
the heifer was killed for experimental purpose on the 8th day of the 
disease (July 18, 1910). The blood contained Th. parva in rare numbers, 
but plasma bodies were found to be very frequent in the glands. 
Note. — The engorged nymphae were collected in due time, and had 
moulted by September 19, 1910. They were placed on Heifer 1088 on 
December 15, 1910, and on Calf 1145 on January 6, 1911, in order to test 
their infectivity {vide Experiment No. 1 C," Nos. 23 and 24). 
7. Ox 1026 was infested on June 27, 1910, with brown nymphae off 
Cattle 700, 917, and 923 (Kef. Nos. 309, 335, and 268), as above. East 
Coast Fever developed after an incubation time of 12 days, and the ox was 
killed on the 16th day of illness for experimental purposes (July 25, 1910). 
The blood contained Th. parva, and the glands showed the presence of 
plasma bodies in large numbers. 
Note. — The engorged nymphse were collected in due time, and moulted 
into adults by September 19, 1910 ; they were used for the infestation of 
Heifer 1088 and Calf 1145 on December 15, 1910, and January 6, 1911, 
