io % ANIMAL LIFE IN AFRICA 



The relation between game- and tick-borne diseases 

 fatal to stock is another question often discussed. 



A great deal of the game country throughout Africa 

 swarms with grass ticks at certain seasons of the year, 

 and though, in many areas, it is exceptional to find many 

 adhering to antelopes and zebras while in good condition, 

 in others the reverse is the case, though to no herbivorous 

 animals are the insects found clinging in such enormous 

 numbers as they are sometimes to the various carnivora. 

 No doubt, speaking generally, game as a whole furnishes 

 a reservoir for ticks of various kinds. There are some 

 five or six diseases which affect stock in South Africa, at 

 present known to be transmitted by ticks. Of these 

 the two most important are biliary fever, which attacks 

 horses, mules and donkeys, and in varying degree other 

 animals, but is only occasionally fatal ; and secondly, 

 east coast fever, a most virulent disease which has des- 

 troyed, and is still destroying, large numbers of cattle in 

 Africa. Writing of this latter, Sir Arnold Theiller, 

 K.C.M.G., the eminent bacteriological expert, says : 



" It has been proved that in east coast fever, a tick, 

 after it has once bitten an animal, can no longer transmit 

 the disease. It must be emphasized here that the 

 popular opinion that ticks pass from one animal to 

 another, and communicate the disease in this way, is 

 wrong. Indeed, males of ticks can live for many months 

 on an animal, but their peculiarity is to remain on that 

 animal, which they only leave accidentally, when they 

 are rubbed off, and since experiments have proved that 

 once they have bitten they become harmless, such an 

 accidental change does not come into consideration in 

 east coast fever." 



Now, as game, like all domestic animals except cattle, 

 appears to be immune from this disease, it therefore 



