Notes on the polymorphism of Trypanosoma gambiense in the blood and its relation to the exogenous cycle in Glossina palpalis

Abstract

The following paper deals with the well-known phenomena of the fluctuation 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 fly are not touched upon in this account. They will, I hope, form the subject of a subsequent paper.