314 MR. S. A NEAVE REPORT ON A JOURNEY 



watershed. These natives had only arrived a month before and had almost 

 certainly introduced this species, since it was absent from the local villages. 



There is also a cockroach^ of which a few specimens were obtained, and 

 which is widely alleged by natives to bite with some severity. This is a 

 surprising £act^ if correct ; though it would appear very doubtful whether 

 these insects draw blood, it is confidently asserted by natives that they 

 produce a small but definite wound in the skin. This insect is locally known 

 as " Nianduli,^^ and appears to be less common near the Luangwa Eiver than 

 on the higher ground. At this place, Fort Jameson, it is not uncommon 

 and is well known to the natives. A considerable collection of ticks, fleas, 

 lice, etc. from various vertebrate hosts was also made. 



Summary and Conclusions. 



We have considerable justification for excluding G, palpalis as the cause 

 of the cases of Sleeping Sickness in the Luangwa Valley. This region has 

 been now so carefully searched by so many independent observers at all 

 seasons of the year, that, quite apart from all climatic considerations etc., it is 

 hardly possible that G. palpalis can have been overlooked. This being the 

 case, all classes of biting organisms must fall mider suspicion. 



The cases found in the Luangwa Yalley by Dr. Leach and their histories 

 have appeared in full in that ofticer's reports. I visited the sites of most of 

 the villages of these cases and managed to elicit a few additional points. 



I found that, of the three cases found by Dr. Leach in the vallev of the 

 Nyamadzi, two were youths and the third, though adult, was unmarried. 

 This would imply that when in their villages they would sleep in the 

 " bachelors '^ hut. Owing to the fact that this hut is not looked after by a 

 woman, it is nearly always neglected and dirty, and is almost certain to 

 harbour floor-maggots, CLiNOCORiDiE (Cimicid^) or any other biting- 

 organisms there may be in the village. It is also this hut, if any, which is 

 used for accommodating travellers. 



For the reasons stated above, I was able to visit the village of only one of 

 the three cases, viz., that of case No. 3 recorded in the Nyasaland Sleeping 

 Sickness Diary, part x, p. 4. This man's village is situated on the right bank 

 of the Nyamadzi on the main road about 4 miles below Nawalia. The chief 

 admitted that the infected native, a youth named Bunyunga, slept in the 

 boys' common hut, and that this hut was frequently accommodating 

 travellers. Government police. Messengers^ etc., passing up and down the 

 main road. 



The only point that the seven cases in the Petauke district would appear to 

 have in common is that they either live near Hargreaves or have more or less 

 frequently visited that place. Too much importance must not, I think, be 

 attached to the fact that all the cases were found on or near the banks of the 



