REPORT 
PROCEEDINGS OF THE EXPEDITION FOR THE 
STUDY OF THE CAUSES OF MALARIA. 
For the purpose of accompanying- this expedition, the Trustees Leave of 
granted me three months' speeial leave of absence from July 28th, Absence and 
& r J ' Instructions. 
1899. 
The instructions I received before starting were to the effect 
that, in placing* my services at the disposal of Major Ross for the 
special objects of the expedition, I should use my best endeavours 
to make my journey as useful as possible to the Museum. 
At the end of this report will be found a summary of the 
results obtained in the collection of zoological specimens 
generally : the malaria investigations, being of greater practical 
importance and having occupied the larger portion of the time, 
are dealt with first. 
The expedition consisted of Major Ronald Ross (late Indian Members of 
Medical Service), Lecturer to the Liverpool School of Tropical [{^ Lxpedl " 
Diseases ; Dr. H. E. Annett, Demonstrator to the School ; and 
myself. Dr. S. van Neck joined the expedition about a week 
after our arrival at Freetown as the Official Delegate of the 
Belgian Government, but took no active part in the operations. 
The objects of the expedition were : — Objects. 
(1.) To find the species of mosquito that carries the malaria 
parasites in Sierra Leone. 
(2.) To discover whether this mosquito breeds in sufficiently 
isolated puddles for its destruction to be possible, 
either by drainage or by the application of substances 
(such as kerosene) which suffocate the mosquito larvae 
in the water. 
