79 



A Preliminary Note on the Extrusion of Granules by 

 Trypanosomes. 

 By W. B. Fry, Captain K.A.M.C. 



(Communicated by H. G. Plimmer, F.R.S. Received May 31, — Read 

 June 15, 1911.) 



During some investigations carried out in the Wellcome Tropical Research 

 Laboratories at the Cordon College, Khartoum, a phenomenon was noticed to 

 occur which would seem to have some bearing on the life-history of the 

 trypanosomata. 



The observations were made whilst employing the dark ground method of 

 illumination, and certain confirmatory evidence was obtained by using a 

 modification of Levaditi's method of silver staining. 



The trypanosome infection of animals referred to in this note was that 

 caused by a strain known in the laboratories as Type I, T. brucei or pecaudi, 

 a strain which our later conclusions lead us almost undoubtedly to regard as 

 a variety of T. brucei. 



It was found that at times during the course of an infection, certain 

 of the trypanosomes extrude from their bodies granules which are thrown off 

 apparently with considerable force, and then appear to possess a certain 

 motility of their own in the blood. 



The phenomenon has been observed both naturally and after drug treat- 

 ment ; its occurrence has been studied principally in the Jerboa, an animal 

 in which the disease runs a chronic course, and it is considered that the 

 extrusion of the granules bears some relation to the periodic disappearance of 

 the trypanosomes from the circulating blood. 



The granule is irregularly spherical in shape and of an apparently constant 

 size, estimated at about - 5 fi. At times a fine corkscrew-shaped filament was 

 observed connected to these granules ; this was seen sometimes immediately 

 after extrusion ; the length of the filament was estimated at four or five 

 times the diameter of the granule. (See accompanying sketch.) 



It is believed that similar granules have been observed in the circulating 

 blood in which trypanosomes were not to be found. Further, that the same 

 granules have been identified in certain organs, -viz., the lung in dogs, during 

 the course of an infection. 



The general appearance and character of the granules were in many ways 

 very similar to those of an extrusion granule, which was subsequently 

 observed by Dr. Andrew Balfour in the same laboratories as occurring in the 



