THE IXODINI 589 



in Egypt, Abyssinia, in parts of Somaliland, and in Portuguese East 

 Africa. Monbata is essentially a human parasite, and is found in huts 

 and houses, principally those of natives. It hides in 

 cracks in the mud walls, in mats and in the dust of Geographical Dis- 

 i i i i e *. i 1-1 ^i. tribution: Bionc 



the floors and bed platforms ; it crawls out, like the mjcs 



bed bug, to bite at night. Its habit of hiding in mats 



explains how it may be carried about by the natives from place to place. 



As is well known, moubata is the invertebrate host of Spirochaeta dut- 

 toni, the parasite of African Relapsing Fever. This spirochaete, on being 



taken into the alimentary tract of the female, penetrates 



J r Relation to Disease 



her ova, thus infecting the larvae. The first nymph 



transmits the spirochaete when it sucks blood, though the exact route by 

 which the parasite reaches the vertebrate host is not definitely decided 

 (see Chapter XII). All the succeeding instars are also infective; a tick 

 once infected may remain infective for an indefinite period. It is also 

 known that the spirochaete may pass to the third generation, though the 

 intermediate stages are fed on uninfected blood. It is very doubtful 

 whether the so-called spirochaete granules from the Malpighian tubes of 

 monbata represent a stage in the life history of the parasite ; similar 

 granules have been found in other species of ticks which have never been 

 infected with spirochaetes. 



The egg of moubata is ovoid in shape, of a glistening dark yellowish 

 colour, and measures '9 by '8 mm. The larva hatches out in from eight 

 to thirteen days, and remains in its egg case until the first nymphal instar 

 emerges. Like savignyi, moubata has four nymphal stages. 



Mr. Hewlett informs one of the writers that Ornithodonts lahorensis is 

 a well known human pest in many parts of Baluchistan ; it is, however, 

 usually found on sheep. It is possible that some of the undifferentiated 

 fevers of the North-West Frontier of India may be associated with its 

 presence. 



SECTION IXODINI 



Ticks with a dorsal shield and a terminal capitulum; the second and 

 third segments of the palps are scooped out, especially in the female; the 

 fourth segment consists of a small papilla of a tactile nature situated in a 

 depression on the infero-lateral surface of the third segment. The spiracles 

 are situated behind coxa IV. Tarsi armed with hooks and a pulvillum. 

 Sexual dimorphism well marked, the scutum of the male covering the 

 whole of the dorsum, leaving only a narrow border usually divided poste- 

 riorly into eleven quadrangular festoons ; in the female the scutum consists 



