Notes on the Polymorphism of T. gambiense, etc. 527 



found within the lymphocytes of guinea-pigs, and by means of the jelly method 

 of examination, the development of these bodies into free spirochetes is 

 demonstrated in the same way that it bas recently been shown that "Kurloff's 

 bodies " also become spirochsetes. I would suggest that these new parasites 

 be called Spirochceta lumbrici. 



KEFEEENCES. 



1910. H. C. Ross and J. W. Cropper, ' Induced Cell-reproduction and Cancel',' London, 



John Murray. 

 1912. E. H. Eoss, ' Eoy. Soc. Proc.,' B, vol. 85, p. 67. 



Notes on the Polymorphism of Trypanosoma gambiense in the 

 Blood and its Relation to the Exogenous Cycle in Glossina 

 palpalis. 



By Miss Muriel Robertson. 



(Communicated by the Tropical Diseases Committee of the Eoyal Society. 

 Received July 5, 1912.) 



I. Introduction. 



The following paper deals with the well-known phenomena of the fluctua- 

 tion in the numbers of trypanosomes present in the blood of an animal 

 infected with T. gambiense, and with the equally familiar question of the 

 polymorphism of the parasites. 



The relation of these factors to the production of infected G. palpalis is 

 also discussed, and evidence is brought forward to show that a certain type 

 of trypanosome is responsible for the carrying on of the cycle in the 

 transmitting host. The actual details of the structure of the trypanosomes 

 and the sequence of developmental stages in the tly are not touched upon 

 in this account. They will, I hope, form the subject of a subsequent paper. 



II. General Condition of a T. gambiense Infection. 

 It is advisable to consider first the fluctuation in the numbers of the 

 parasites. It is important to note here that a close study of any given infection 

 brings out very clearly that the multiplication of the trypanosomes occurs in 

 the circulating blood-stream. Search has also been made for any type of 

 multiplication in the cells of the lung, liver, and spleen, so far entirely 

 without success. Moreover, the invariable correlation between a rise in the 



