PROTOZOA IN BRITISH EAST AFRICA 
83 
cattle, a disease also frequently spoken of under the local 
name Texas Fever, or Tick Fever. The parasite appears in 
the blood about a week or ten days after inoculation or infection 
of a susceptible animal by means of ticks. In multiplying, 
the red blood corpuscles are destroyed, causing the host to 
become very anaemic. The mortality is very variable, and 
in the case of cattle imported from clean land to infected 
pastures it may be high. On the other hand calves reared on 
infected pastures less frequently show any marked symptoms, 
although their blood contains the Babesia and is capable of 
maintaining the infection of ticks. This resistance may be 
broken down by means of a concomitant disease or when the 
vitality is much reduced. 
Babesia canis. Piana and Galli- Valero. 
Hosts. Dog. 
Distribution. Europe (France), Asia, and Africa. It has 
not yet been described from America or Australia. We do not 
know of any area in East Africa which is free of the parasite. 
Morphology. Very similar to B. bigemina of cattle. This 
parasite has been the special study of Nuttall and Graham- 
Smith, who have described the development within the 
mammalian host. According to these authors a free pear- 
shaped body enters a red blood corpuscle and there first 
becomes rounded and then amoeboid. At this time nuclear 
changes are taking place which result in a bifid budding of 
the body. Finally, formation of twin pear-shaped parasites 
occurs, and the corpuscle is destroyed so as to allow of these 
forms becoming free and available for the attack of new 
corpuscles. 
Christopher has followed the development within the 
tick — Bhipicephalus sanguineus — which is found to transmit 
the infection in India, and has traced into the ovaries and 
salivary glands bodies which he regards as forms of the 
Babesia. 
Transmission. Loundsbury and Robertson were the first 
to prove transmission of Babesia canis by means of Haemaphy- 
salis leachi — the common dog tick — in South Africa. Infection 
Vol. II.— No. 3. 
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