PREFACE 
IN 1 90 1 , one of us (Dutton) saw trypanosomes in the blood of a European who was 
suffering from an illness characterized by a peculiar combination of symptoms. I5, 16 
The clinical picture presented was one which might be confounded with a tropical 
cachexia. In addition, the trypanosomes were rarely present in the ringer blood, and 
were never very numerous. The discovery of parasites in this case made it necessary 
to enquire whether their occurrence was merely a curious pathological coincidence or 
specific. If the latter were assumed to be the case, it at once became probable that 
some tropical illnesses which had previously remained unclassified, or had been 
wrongly diagnosed, would be found to be cases of trypanosomiasis. 
Before the details of study of this case were published in the Thompson Yates 
Laboratories Report, May, 1902, a trypanosome was found in a blood film taken from 
a native child in the Gambia ; and the discovery of a second case of human trypano- 
somiasis made it probable that the first was not altogether a curiosity. 16 The rarity 
with which the parasites appeared in the peripheral circulation of the European case, 
and their fewness when they were present, fully explained how easily they might 
escape detection and permit the malady in which they occurred to remain unidentified. 
The Committee of the Liverpool School of Tropical Medicine realized the 
possible importance of this new parasite as a cause of disease and sent this Expedition 
to Senegambia to make further investigations on the subject. 
While the members of the Expedition were in Gambia, the first European 
case remained in Liverpool under the care of Dr. H. E. Annett, who recorded 
observations on the course of the disease, and experimented with the parasite. The 
results of his work are incorporated in this report. 
Our thanks are due to Professor Herdman, Mr. H. C. Robinson, and 
Mr. J. Johnstone for identifying some species of birds, bush rats, and frogs. 
We give a list of references to various articles on trypanosomiasis which may 
be useful to those interested in the subject. 
The Communication 4 written by Professors Bovce, Ross, and Sherrington, has 
spared us the task of discussing the history of the discovery of human trypanosomiasis. 
To them, who so clearly defined our situation, and to all, both in England and in 
Africa, who have aided us in our work, we are most grateful. 
Our thanks are particularly due to Dr. Annett for the constant kindness with 
which he has met our many trespasses on his time, and to Dr. H. Wolferstan 
Thomas and Dr. S. F. Linton, tor their goodness in correcting the proofs. 
J. E. D. 
J. L. T. 
jftb September, 1 903 
