98 Biology 



and nymphs were observed to feed for very variable periods; thus 15 

 ticks, of which accurate records were kept, fed respectively for 20, 

 20, 25, 30, 30, 40, 40, 40, 45, 55, 60, 80, 100, 100 and 125 minutes. 

 Nymphs (1st stage), of which 5 were timed whilst feeding, took 10, 

 10, 25, 30 and 60 minutes before they dropped off the host. They 

 usually feed at night under natural conditions, but they may attack 

 persons by day as Wellman has observed in native huts in Angola 

 (personal communication). 



The effect of the bite has been repeatedly described : 



Livingstone (1857, p. 383), who was bitten by the " tampan," states 

 that the tingling sensation at the point bitten lasted for about a week. 

 He refers to the fever which may follow the bite as being well-known to 

 the natives. Murray (1877, p. 182) quotes Dr Welwitsch as stating 

 " that the pain of the bite is not felt until two hours after it has been 

 inflicted, but it makes up for the respite by continuing painful and in- 

 flamed for from 12 to 24 hours thereafter." 



Brumpt (1901, pp. 578 — 580) was the first to study the effects of 

 their bites, allowing himself to be bitten by 43 moubata collected in 

 Somaliland, where " tick fever" prevailed. He suffered no ill effects and 

 states that the bites were not troublesome except when they attack man 

 in large numbers, producing anaemia consequent upon loss of blood. 



Dutton and Todd (1905 b, p. 123) say that the bite even of a small 

 tick is painful; they allowed a tick to bite a monkey: "Immediately after 

 feeding, a small crust of serOsanguinolent fluid forms at the site of the 

 bite. Surrounding it is a roseola about 2 mm. in width. Two hours 

 later the central clot is surrounded by 2 concentric zones, each 2 mm. in 

 width ; the first colourless, the second ecchymotic. Six hours later the 

 clot has become almost black, and is placed at the apex of a slight, 

 colourless wheal, bordered by an ecchymotic zone about l - 5 mm. in 

 width." 



Wellman (1906, 1907) writing from personal experience in Angola, 

 states that the bite is very painful, the swelling and irritation (especially 

 in Europeans) not subsiding for days. "The wheals are hard, raised, and 

 itch and swell most disagreeably if scratched, and this even a week 

 after being bitten. The bite of young ticks (nymphae) is said by 

 the natives to be more severe than that of the adults." Wellman 

 experimented upon himself and is convinced that this is generally 

 the case. He states (in MS.) that in some natives, usually aged 

 individuals, the bite may scarcely leave a mark. (From this it is 

 evident, as is the case with mosquito bites, that immunity to its effects 

 is acquired.) 



