MALARIA EXPEDITION TO NIGERIA 
243 
July 21 More caught males were added. 
,, 23 Re-fed five females ; one would not feed ; others had died. 
„ 27 Re-fed three females ; two dead on the water showed unde- 
veloped ovaries, and empty spermathicae. Added five more 
males from native town. 
„ 29 All had died. 
The following three experiments were undertaken to ascertain whether males 
from a certain batch of eggs from one adult female could fertilise the females of the 
same batch ; Experiments XIII and XIV seem to contradict one another in their 
results. They also serve to show that the males directly after hatching reach sexual 
maturity very quickly, and are able to fertilise. 
Experiment XIII 
July 1 Nine females developed from pupae were fed on blood of one 
of us and introduced into a small cage together with banana 
and water. 
3 Nine females re-fed. 
5 Re-fed eight females. 
7 Re-fed six females ; one dead on water ; abdomens swelling. 
9 Re-fed five females ; one would not feed ; no eggs laid. 
1 1 Re-fed six females ; one egg found on water. 
13 Re-fed five. One would not feed. 
1 5 Re-fed five. Few eggs laid irregularly on water ; one female 
dead on water shewed fully developed ova with chitinous 
covering. 
18 Re-fed two females ; three would not feed ; single egg of 
1 ith had disappeared ; those of 15th had not hatched out. 
,, 20 Re-fed four females ; one would not feed ; more eggs laid ; 
those of 15th had not hatched. 
,, 23 Re-fed three females ; one dead ; more eggs laid. 
,, 25 Females would not feed. 
„ 27 Re-fed three females ; no males present ; more eggs laid. 
„ 29 Females would not feed. 
„ 3 1 Two females dead ; one only fed ; no more eggs. Introduced 
six freshly-hatched males into cage. 
Aug. 2 Some eggs on water ; pregnant female dead — ovaries contained 
eggs with chitinous covering. Eggs of 27th not hatched. 
„ 4 Eggs of 2nd not hatched. 
