MALARIA EXPEDITION TO NIGERIA 
24 
July 7 More eggs laid ; re-fed four of the five remaining females, the 
other would not feed. 
„ 9 Eggs of seventh hatched out. Re-fed four females ; one 
would not feed. 
„ 1 1 Few more eggs laid. Re-fed two females ; three would not 
feed. 
„ 12 Eggs of yesterday hatched out. 
„ 13 Re-fed five females ; no more eggs laid. 
„ 1 6 Re-fed three females ; numerous eggs laid ; one female dead 
on the water ; two appeared thin. 
„ 17 Eggs of 1 6th hatched out. 
„ 18 Re-fed four females ; one would not feed ; no ova. 
„ 20 Re-fed three females ; eggs laid. 
,, 21 Placed more males in cage. Eggs of yesterday hatched. 
„ 23 Re-fed one female ; others escaped. 
,, 25 The remaining female would not feed ; more eggs laid. 
„ 26 Eggs of yesterday hatched out. 
„ 27 Remaining female dead on water. 
Thus our surmise that a long flight was required for copulation proved false, 
since the ova in the second of the two experiments just detailed had been fertilised and 
hatched out. Why fertilisation did not take place in the larger cage is difficult to 
explain, unless owing to the comparative small number of mosquitoes, both males and 
females, in so large a space, the opposite sexes seldom met. It is to be noted that in 
this experiment eggs were laid in water in an iron tank preferably to that in an arti- 
ficial soil puddle, and further, that although fertilisation did not take place still the 
ovaries developed apparently normal ova, which, however, did not produce larvae. 
It is further to be remarked that, with a regular supply of blood (every other 
day), eggs are laid within eight days of the birth of the adult female from the pupae; 
and that they continue to be deposited every second or third day afterwards, if water 
is available, until the death of the insect. 
In these experiments it is seen that females in confinement in cages may live 
and be fertile for a period of at least seven weeks ; from which it may be surmised 
that under natural conditions they might live much longer. 
The following experiment shows that even in the absence of males, the 
ovaries develop ova. 
Experiment X 
July 17 Introduced five females hatched from pupae ; no males added. 
The females were fed on blood. 
