189 



wild animals are more virulent than those transmitted by Glossina. 

 Blood taken from an antelope {Cervicapra anindinum) near Zambi 

 (Lower Congo) was mixed with a citrated isotonic solution and left 

 in a tube all night. The next day it was examined for trypanosomes, 

 but none were found. A native sheep was then given a subcutaneous 

 injection of the citrated blood and after 4 days showed an enormous 

 number of T. congolense in the blood, dying on the 6th day. Similar 

 sheep living in regions infected with T. congolense and where Glossina 

 is present exhibited the disease in a chronic form, with very few 

 trypanosomes in the blood, and with no symptoms of the rapid 

 development exhibited in the experimental case. 



Croveri (P.). Osservazioni sulla Biologia della Glossina pallidipes 

 della Somalia Italiana e sulla Trasmissione agli Animali domestici 

 della Tripanosi detta " Ghendi."~^/m. (Vlgiene, Rome, xxix, 

 no. 7, 31st Julv 1919, pp. 432-447. [Received 16th October 

 1019]. 



In Italian Somaliland measures against trypanosome diseases come 

 next in importance to those against rinderpest. No sure method of 

 immunisation or cure exists, and the only possible remedy is to combat 

 the vectors, since the practice of moving herds away from districts 

 infested with them entails the avoidance of rich pastures and a nomadic 

 life unfavourable to stock. 



The first observations on trypanosomiasis in Italian Somaliland 

 were published in 1911 by Martoglio, who distinguished three forms : 

 " Ghendi," due to Trypanosoma somalilense, tran^mitted by Glossina 

 pallidipes, and common to all domestic animals in the colony ; ' ' Gobiat " 

 or " Gumul," due to Trypanosoma cellii, transmitted by an unknown 

 Dipteron and affecting bovines ; and " Salaf " or " Ducan," due to 

 a trypanosome that Martoglio identified as the agent of surra, 

 {T. evansi), and transmitted to camels by an unknown Tabanid. 



The present author has conSned his investigations to " Ghenii.' 

 A less common form of trypanosomiasis that occurs in wooded localities 

 infested with Tabanids and far from rivers appears to be that known as 

 " Salaf." 



The observations were made on the middle and lower Shebeli 

 River and probably also apply to the valley of the Juba, as the con- 

 ditions there are similar. The only species of Glossina found was 

 G. pallidipes, and experiments showed that this fly was able to transmit 

 the disease. As a period of 17-19 days elapses between the infecting 

 feed and the capacity for transmission, it is probable that the try- 

 panosome undergoes an evolutionary cycle in the fly. The situations 

 preferred by G. pallidipes are wooded spots, covered with low, 

 dense bush and near stagnant or slow-flowing water. Such 

 localities are limited in area during the dry season, but extend 

 considerably during the wet season, so that the infested zone u 

 then increased. G. pallidipes avoids open and cultivated areas in 

 general, though it is found in banana and rubber plantations 

 and among low trees. On sunny days it bites from early dawn 

 up to about 8 a.m., re-appearing about 4 p.m. and disappearing 

 again at nightfall. On cloudy or rainy days it bites during the whole 

 day, and on bright moonlit nights only if it is disturbed ; it does not bite 



