142 INSECTS AND MAN 



the Arabs from the East Coast, and with traders from 

 the Southern Portuguese territory, where they existed in 

 Livingstone's time ; they occur all along the trade routes, 

 and in many villages along the Congo between Kasongo 

 and Ponthierville, though in the native villages an hour's 

 walk inland they are quite unknown. 



Ornithodorus moubata passes through an interesting 

 life-cycle, differing in many respects from that of the 

 other ticks described in this book. The adults are capable 

 of rapid locomotion, though their feeding is slow ; a well- 

 grown female, for instance, will feed continuously for three 

 hours, becoming distended with blood to the size of a 

 cherry before dropping off. It is obvious that only 

 sleeping people can be attacked with any degree of 

 satisfaction to the ticks, and, to that end, they are 

 nocturnal. When disturbed they will pretend to be dead 

 for hours at a stretch, curling up their legs and remaining 

 motionless. The bite of one of these ticks is very painful 

 and unpleasant, quite apart from the probability of infec- 

 tion. When about to partake of a meal, which may take 

 place at any part of the body, the tick first sees that its 

 forelegs have a firm hold, then, lifting up its hind quarters, 

 it literally buries its mouth parts in its host's flesh. 

 While feeding excrement is voided, a filthy habit common 

 to many ticks, but important, as will be seen later. At 

 the same time a considerable quantity of a clear fluid 

 often oozes from glands opening between the bases of the 

 first and second pair of legs. 



The adult female tick is of a dark brown colour, blotched 

 irregularly with yellow ; when gorged with blood and about 

 to oviposit it measures approximately 12x10x7 milli- 

 metres. The number of eggs laid by each female depends, 

 to some extent, on the amount of blood she has imbibed ; 

 the greater the amount of blood food, the larger the number 

 of eggs, about one hundred and forty being the average 

 (fig. 41). The eggs are golden brown in colour, and they 



