377 



Further Researches on the Extrusion of Granules by Trypano- 

 somes and on their Further Development. 



By W. B. Fry, Major B.A.M.C., and H. S. Ranken, M.B. (Glasg.), M.R.C.P. 

 (Lond.), Captain B.A.M.C. (With a Note on Methods by H. G. Plimmer, 

 F.R.S.) 



(Communicated by H. G. Plimmer, F.R.S. Received December 23, 1912— Read 



February 6, 1913.) 



[Plates 9-11.] 

 Introduction. 



In March, 1911, in the course of some work on trypanosomes carried out 

 at the Wellcome Tropical Research Laboratories, Khartoum, the extrusion of 

 certain granules from trypanosomes was observed by one of us (W. B. F.). 

 The Director of the Laboratories, Dr. Andrew Balfour, was informed of 

 these observations, and he himself shortly after observed a somewhat similar 

 extrasion of granules from Spirochetes (spirochetosis of fowls), an account of 

 which he published.* 



In June, 1911, a preliminary note on the subject was communicated to the 

 Royal Society by one of us (W. B. F.). Since then, a great deal of work has 

 been done on the subject by us conjointly, but for the most part independently ; 

 by one of us (W. B. F.) at Khartoum and in London, by the other (H. S. R.) 

 at Yei in the Lado Enclave. 



As will be seen, the results recorded in the course of this paper go far to 

 confirm the conclusions arrived at in the preliminary note, i.e. that the 

 phenomenon is one connected with a stage in the life-history of the parasite, 

 especially in chronic trypanosomiasis, in which it is found that the trypano- 

 somes disappear from the blood of an affected animal for considerable 

 periods. 



These observations offer, too, an explanation of the infectivity of fluids, 

 blood for example, which, while showing absolutely no trace of trypanosomes, 

 will infect susceptible animals, a fact that all workers on trypanosomiasis are 

 acquainted with ; they also throw light on that condition which has been 

 spoken of as " a possible ultra-microscopic stage " in these diseases. 



Methods. 



In the earlier part of these investigations two methods were principally 

 used, they were : — 



* 'Brit. Med. Journ.,' April 1, 1911. 

 VOL. LXXXVI. — B. 2 F 



