33 



Trypanosome Diseases of Domestic Animals in Nyasaland. 

 III. — Trypanosoma pecorum. Development in Glossina 

 morsitans. 



By Surgeon-CJeneral Sir David Bruce, C.B., F.E.S., A.M.S. ; Major A. E. 

 Hamerton, D.S.O., and Captain D. P. Watson, E.A.M.C. ; and Lady 

 Bruce, B.R.C. (Scientific Commission of the Royal Society, Nyasa- 

 land, 1912-14.) 



(Received March 25,— Read April 30, 1914.) 

 ' [Plate 2.] 



Introduction. 



In a previous paper* the morphology of this species of trypanosome and 

 its action on animals were described. In this it is intended to give an 

 account of its development in Glossina morsitans. 



This trypanosome belongs to the group in which the development takes 

 place first in the gut, then passes forward into the labial cavity of the 

 proboscis, and finally reaches the hypopharynx, where the trypanosomes 

 revert to the original " blood-forms " and become infective. There is no 

 infection of the salivary glands. 



The Development of T. pecorum in G. morsitans. 



Seven experiments were carried out with laboratory-bred flies. Five were 

 positive and two negative. 



Table I. — Laboratory-bred Flies. 



Date. 



Expt. ; fl 



No. of 



ies 

 used. 



Expt. 

 positive or 

 negative. 



No. of 

 infected flies 

 found. 



No. of days 

 before flies 

 became infective. 



Mean 

 temperature. 



1912. 

 May 16... 

 July 2... 



1913. 

 Jan. 3... 



„ 7... 

 Feb. 10... 



» 24... 



546 



22 



524 



20 



1732 



60 



1737 



40 



1853 



25 



1950 



33 



2115 



40 



53 

 37 



19 

 24 

 21 



69° F. (20 -5° C). 

 65° F. (18 -3° C). 



84° F. (28 -8° C). 

 84° F. (28 -8°C.). 

 84° F. (28 -8° C). 

 84° F. (28 -8°C.). 

 84° F. (28 -8° C). 



; Koy. Soc. Proc., : B, vol. 87, p. 1 (1913). 



VOL. LXXXVIII. — B. 



