334 



TRYPANOSOMA PEC AUDI 



[CH. 



of view that longipalpis is the species which in this region 

 constitutes the reservoir fly of T. pecaudi, to the exclusion of 

 the others. The incubation period of the parasite in G. longi- 

 palpis is about 23 days. In addition, 60 G. tachinoides were fed 

 on a guinea-pig infected with T. pecaudi and then on a series 

 of healthy guinea-pigs. Two of these guinea-pigs became 

 infected, giving an incubation period in the fly of 26 days, 

 whereas the others remained normal. In this region experi- 

 ments with G. palpalis gave entirely negative results, but 

 Bouffard previously succeeded in the transmission of T. 

 pecaudi by means of this species, though only with difficulty. 



Fig. 77. Culture of T. pecaudi, in the intestine of G. palpalis ( x 1200). 

 a, h, normal forms from the circulating blood ; 1-5 forms 18 hours after 

 ingestion; 1,2, involution forms; 3, slender form; 4, 5. large forms; 

 6, 7, large forms 56 hours after ingestion. (After Roubaud.) 



In the Nigerian Sudan, Bouet and Roubaud, during the dry 

 season, found that the morsitans of that region were naturally 

 infected with T. pecaudi. 



It appears, therefore, that longipalpis and morsitans are 

 the two most favourable hosts for this parasite, and that 

 tachinoides and, exceptionally, palpalis may also be infected. 



Every infected fly that was dissected contained flagellates 

 along the whole of the digestive tract from the proboscis 

 to the hinder intestine. The trypanosomes multiply in the 

 intestine up to 48 hours after ingestion in a modified form 



