192 REPORT OF THE HARVARD AFRICAN EXPEDITION 
“1. A. luteocephalus and A. apicoannulatus were found to transmit the disease 
in all respects in the same manner as A. aegyplt. 
2. Two lots of E. chrysogaster were allowed to feed on infected monkeys. 
One of these lots produced typical infection when later fed on normal monkeys; 
the mosquitoes of the other lot failed to convey the virus through bite, but proved 
infective when macerated and injected into a normal monkey twenty-four days 
after their original infecting feed. 
3. Attempts to transmit the disease with A. apicoargenteus gave entirely 
negative results, either through their bite or through being injected into normal 
monkeys at various intervals after they had fed on infected animals. 
4. A. longipalpis, A. welmani, and Culex nebulosus failed to feed on infected 
monkeys, and consequently the question whether or not they can transmit 
yellow fever could not be determined. 
5. The pathologic changes in the monkeys which died after being bitten by 
A. luteocephalus, A. apicoannulatus, and E. chrysogaster were typical of yellow 
fever, and the virus apparently suffered no loss of virulence by its passage 
through these mosquitoes.” 
It is possible, of course, that in a larger series of experiments some of the 
species of Aédes which gave negative results might give positive ones. At least 
no one would be justified in rigidly excluding them as possible transmitting agents 
in yellow fever. 
Philip ! has still more recently shown that three other species of Stegomyia are 
capable of transmitting the disease to monkeys. These are Aédes vittatus, 
Aédes africanus, and Aédes simpsont. This brings the list of mosquitoes shown to 
be capable of transmitting yellow fever up to a total of seven. 
Legendre * has maintained that there are two races of Aédes aegypti, one a 
large insect capable of transmitting yellow fever, the other a small one of oceanic 
and Indian race incapable of transmitting the disease. However, from the investi- 
gations of Hoffmann * and Brug,’ who performed cross-breeding experiments in 
Cuba as well as at Java, these two strains of Aédes (one Cuban and the other 
Dutch East Indian), appeared to be identical. Hindle® also has shown that 
yellow fever can easily be transmitted from monkey to monkey through the bite 
of an Indian strain of Aédes aegypti. 
Of the other mosquitoes in Liberia dangerous to man, Anopheles and Culex 
fatigans were also found to be common. Of these A. gambiae and A. funestus 
are the most prevalent and are probably the species which are usually concerned 
in the transmission of human malaria in Liberia. The eighteen species of mosqui- 
toes collected on the present Expedition in Liberia have kindly been studied 
and identified by Dr. F. W. Edwards of the British Museum. There are six 
species of Aédes, two of Anopheles, and five of Culex. Bequaert has listed one 
hundred and twenty species and eleven varieties of mosquitoes from the Belgian 
1 Philip: Amer. Jour. Trop. Med. (1929), IX, 267. 
2 Legendre: Presse Méd. (1929), XX XVII, 459. 
’ Hoffmann: Meded. Dienst Volksgezondheid in Nederl-Indie (1929), XVII, 182-183. 
4 Brug: J/bid., p. 184. 
6 Hindle: Trans. Royal Soc. Trop. Med. and Hyg. (1929), XXII, 405. 
