40 Arachnid a and Myriopoda 



interior it frequents most camps of long-standing which are 

 inhabited by human beings and their domestic animals. They 

 are extremely common in the dusty soil surrounding the wells and 

 water-holes. In the waterless Haud and Nogal Valley they are 

 most frequently found under large trees, especially when these 

 are in isolated positions, as at Ged Aboukir on the Arori Plain, 

 and afford the only shade for miles to the shepherd and his 

 flock during the heat of the day. Ornithodoros savignyi is 

 capable of living for months without a fill of blood in the soil, 

 into which it burrows to a depth of half to one inch, lying 

 dormant there until the ground is disturbed by the foot of 

 man or beast. In captivity it will live for six months or 

 more in a tightly stoppered bottle half-filled with dry earth, 

 without food or water. It will attack human beings, camels, 

 cattle, mules, donkeys, sheep and goats with equal vigour. It 

 seldom climbs much higher than the ankle in human beings and 

 the hocks in animals." Drake-Brockman remarks that the best 

 and cheapest method of destroying these ticks when they swarm 

 in confined areas, such as the immediate vicinity of wells, is to 

 cover the whole infested area with dry grass and brushwood, after 

 harrowing or disturbing the surface, and then set fire to the 

 grass all round simultaneously, so that the fire will gradually burn 

 its way towards the centre. Native soldiers should rub their feet 

 and ankles with turpentine when entering localities where the 

 tick is known to occur and to be infected with the spirochaet of 

 relapsing fever. 



Eelapsing fever is known to occur in Persia ; Wosnissensky's 

 and Dschunkowsky's observations seem to make it clear that the 

 spirochaet causing the disease in that country is conveyed by a 

 tick of the genus Ornithodoros. The identity of the tick concerned 

 is still uncertain ; it is either Ornithodoros tholozani, 0. canestrinii, 

 or 0. lahorensis. 



Ornithodoros pavimentosus, Neumann. 



A third African species of Ornithodoros (0. pavimentosus) has 

 also been found in South Africa (Namaqualand). There are two 

 distinct eyes on each side of the body of this tick as in 0. savignyi, 

 but it differs from that species in having the granules contiguous 

 and flattened, instead of rounded (hence the name pavimentosus). 

 It is possible, however, that this tick is only a variety of 0. savignyi. 

 According to Schultze, the habits of 0. pavimentosus are very like 

 those of 0. moubata. He says it is common at resting-places, 



