TRYPANOSOMIASIS EXPEDITION TO SENEGAMBIA 
45 
VI. RESULTS OF INOCULATION OF THE GAMBIAN HUMAN AND 
EQUINE TRYPANOSOMES IN EXPERIMENTAL ANIMALS 
Inoculation Experiments 
The experiments have been divided into two sets of tables, Human 
Trypanosome and Equine Trypanosome. In these divisions all the inoculated 
animals of the same species have been arranged according to the passage or the 
parasite and, as far as possible, all those of the same strain have been grouped 
together. In every case the strain of the parasite inoculated has been noted. In all 
the inoculations the blood was mixed with sterile sodium citrate solution (page 2). 
All the rats and mice used in the following experiments were tame ones with 
the exception of a few bush rats and some wild mice — in the tables these animals are 
specifically marked. 
All the animals were carefully and repeatedly examined before inoculation, to 
ascertain if they were free from Trypanosomes. 
Resume of Inoculation Experiments 
We think that it would be premature and unprofitable to enter upon a 
detailed discussion of the properties and identities of these two Gambian Trypano- 
somes, based upon the experiments which we present in this report. 
We fully recognize the importance of determining whether these two parasites 
are the same, or whether either is identical with any previously described pathogenic 
Trypanosome. At present we are inclined to believe that they are not the same 
species ; our reasons for this opinion are : — 
1. The more chronic course of the disease produced by the human parasite 
in all animals, perhaps with the exception of the goat. 
2. Tame rats infected with the horse parasite certainly die from its effects, 
while, on the other hand, we have no evidence to show that the 
infection which has occurred in tame rats, inoculated with the human 
parasite, has been the only cause of death. 
3. The modes in which the human and horse parasites appear and dis- 
appear in the blood of inoculated animals, during the course of the 
disease, is not the same ; thus, in rats inoculated with the former 
parasite, there is a marked periodicity of entrance and exit of the 
parasite in the peripheral circulation, in the case of the horse parasite 
this periodicity is not a marked feature. 
