240 REPORT OF THE HARVARD AFRICAN EXPEDITION 
the country. Actually the infection is not common in Liberia. Only one 
case was brought to our notice by Dr. Willis while we were in the country. 
The individuals observed in Liberia afflicted with this parasite are usually 
travellers coming from more central and drier regions of Africa. 
Roussel! has recently shown that repeated local injections of such drugs 
as cocaine, formalin, chloroformization of the parasite, etc., as well as general 
chemotherapeutical measures such as the intravenous injection of novarseno- 
benzol and tartar emetic and the intramuscular and intravenous injections 
of emetine, as well as the ingestion of stovarsol, all failed to destroy the parasite 
Dracunculus medinensis. In three patients he repeatedly tried all these methods 
of treatment without success. In one instance in which more than 100 mi- 
crofilariae were expelled, the patients had received successively 4 85 grams of no- 
varsenobenzol in seven injections and ten injections of emetine. The adult 
parasite apparently remained unaffected. Roussel has also shown by injections 
of lipiodol into the body cavity of the parasite at the extremity which points 
to the skin, that excellent radiograms showing the location of the worm some- 
times may be obtained. These radiograms illustrate the impracticability of 
attempting to remove the parasite by surgical operation owing to its very 
extensive ramifications. The radiograms in addition show that the worm is 
found in the connective tissue and not in the muscles. 
ONCHOCERCIASIS 
Infection with Onchocerca volvulus was first observed in the interior of Libe- 
ria at an altitude of some 900 feet. In this same region we observed in consider- 
able numbers a species of black fly, later identified as Simuliuwm damnosum. At 
one of our camps situated at Gbanga, near the geographical center of Liberia, 
an especial search and study was made regarding this fly. We were successful 
in finding its breeding place about a mile from our camp in a swiftly-flowing 
stream (Nos. 176, 177) whose banks were bordered by narrow belts of low 
forest or by rice fields. 
The larvae and pupae of the flies were found fixed on the bottoms and 
sides of stones which were lifted from the swiftly-flowing stream, and attached 
to leaves of branches of trees immersed in the water. They apparently ad- 
here to the stones and leaves by means of a circle of spines at the caudal end 
and a sticky substance secreted from the mouth. The pupa is enclosed in a 
boat-shaped cocoon (Text Fig. No. 6, page 857). A number of the adult flies 
were collected from the banks of the stream. They are small, about three milli- 
meters long, and almost black (Text Fig. No. 4), and are commonly found in 
the bush and grass in the vicinity of the water. A more complete entomological 
description of them is given on page 852. They seem to prefer shade and hu- 
midity and will not bite in the bright sunlight. Only the female has been found 
biting during the day in shady places. The insect makes no sound when flying 
and alights quietly upon the skin. Bequaert has carefully studied and described 
the larvae and pupae of this fly. The adult flies captured on the banks of this 
1 Roussel: Bull. Soc. Path. Exot. (1928), X XI, 103. 
