205 



NuTTALL (G. H. r.) & HixDLE (E.)- Conditions influencing the 

 Transmission of East Coast Fever. — Pai-a.uiology, Cambridge, 

 vi, no. 3, Oct. 1913, pp. 321-322. 



Tlie life-cycle of Theilevia pawa, the parasite of East Coast 

 Fever has not yet beeu elucidated. Nor has Gonder's account 

 of the life-cycle of the parasite within the invertebrate host, 

 Rliipicephalus appendiculatus , been confirmed. 



A summary of the experiments carried out by the authois on 

 the transmission of East Coast fever permit of the following' con- 

 clusions, seven in number: — (1) Infected ticks do not produce 

 infection during: the first two days when feeding on cattle: 

 (2) infected ticks are still infective after feeding- upon a rabbit for 

 three days : (3) heating infected ticks to 37° C. for three days 

 does not lender them infective during the first two days after they 

 become attached to the host; (4) the partial feeding of infected 

 ticks for two days, followed by starvation for IT days, renders 

 them non-infective; (5) inoculations of emulsions of infected 



Errata. 



Page 204, lines 12, 15, 32 and 35, for *' Sick Paralysis " read 

 " Tick Paralysis." 



:^2720 



action : for instance, the parasite which occurs in the dog is only 

 capable of setting up the disease in the dog. 



Usually about 8-10 days after the animals have been attacked 

 by the ticks they show high fever, loss of appetite, etc., and a 

 large number die in a few days— anything from 25-100 per cent, 

 succumbing to the infection. In severe cases, the number of 

 corpuscles in the circulating blood may be reduced to a third or 

 less. When animals recover they do so slowly, and the parasites 

 grow very scarce in the blood. 



The piroplasmosis of cattle is due to at least two species of 

 Firoplasma, P. bovis and P. divergens. The latter parasite is 

 transmitted by Ixodes ricinus, the common European cattle tick. 

 The well-known Texas fever of the United States, generally known 

 as "' redwater," is due to P. bovis, and appears to be transmitted 

 in nature almost solely by Boophiliis annulatus and its varieties. 



" Eedwater " in horses is due to two distinct parasites. When 

 a horse recovers from infection by the one, it is still susceptible 

 to infection by the other. Dermacentor reticiilatvs has been 



.322 11 ^ 



