OF THE NATIVE DOMESTIC WATER-RECEPTACLES AT LAGOS, &Cow 129 
impossible without actual residence, as the mosquito of one house is not 
always that of the next. The superior accuracy and finality obtained by dealing 
with the larve breeding in the native yards of the township is apparent, and I 
hope that a similar examination of the larve of each native town will be attempted. 
We shall then be placed in a position to compare accurately the geographical 
distribution of the mosquitos with that of the indigenous diseases. Very useful 
information will, I feel sure, be obtained by such a comparison, for all the chances 
are in favour of that insect, which breeds and lives in the immediate vicinity of 
human dwellings, playing a preponderating part in the transmission of human 
diseases. Such a study of the larve would also supply the materials required for 
the accurate identification of really distinct species ; a subject which is at present 
in considerable confusion. 
The results obtained by 8 months’ investigation are presented below in tabu- 
lated form, and furnish some surprises. But to render the tables intelligible it 
will be necessary first to explain shortly the geography of the places named in 
them. 
The town of Lagos is built upon the islands of Lagos and Iddo, which are 
connected by a long bridge. These islands are sandy, low-lying and swampy. 
It will be seen on the map that the town is divided into 4 Sanitary Divisions, 
A, B, C, D, each of which is sub-divided into districts lettered alphabetically. 
Ebute Metta is a town built upon the mainland, being joined to Iddo by a long 
bridge. It is the headquarters of the Government Railway, and is surrounded 
by swamps. 
During the eight months, August to March inclusive, 18 different species of 
insect larvee, of which 6 were mosquitos, and 5 Crustaceans were found in the 
native domestic water-receptacles examined, as shown in the following list :— 
Insect Larve. 
Stegomyia fasciata, F. 
Pectinopalpus fuscus, Theo. 
Culex duttoni, Theo. 
Culex tigripes var. fusca, Theo. 
Culex nigrocostalis, Theo. 
Pyretophorus costalis, Loew. 
Chironomus (3 species). 
Psychoda (2 species), 
Drosophila (1 species). 
Ephemeride. 
Crustacea. 
Cyclops simillimus, Brady. 
Daphnia sp. 
Cypris (2 species). 
Atthegella africana, Brady, 
