8 4 
genera of the Culicidae are not nearly so great as in 
the case of the larvae. 
By keeping under observation a number of 
nymphae, some will be seen to become less inclined 
for active movement, and the abdominal segments 
Fig. 30 . Nymphae of an Anopheline and Culex sp. 
(tail) may be extended horizontally. Soon after these 
changes the adult insect emerges through a crack in 
the chitin of the back of the thorax. The process as 
seen in Anopheles is very fully described by Nuttall and 
Shipley. 1 
Examination of Nymphae 
1. Observe that when first they appear the 
nymphs are light in colour, but darken very considerably 
later. 
2. Note that just before the hatching of mos¬ 
quitoes the nymph lies with the tail extended, and that 
silvery marks may be seen, due to air lying under the 
chitin. 
3. Observe the emergence of the imago. 
Examine the nymphs of Anophelines , Culex , 
1. Journal Hygiene, vol. 1, part II. 
