7 6 
Observe bow beautifully certain baits resembling fan- 
palm leaves are shewn (palmate bairs) (Fig. 65). 
2. The Method of Feeding of Anophelines .— 
Observe witb a lens tbe action of tbe feeding brushes 
and the currents they produce on tbe surface of the 
water. Note tbe rotation of tbe bead so that, whilst 
feeding, tbe ventral surface of the bead is uppermost. 
3. The Food of Larvae. —Tear a larva to pieces 
witb a needle and remove a small portion of tbe dark 
central mass of food material filling tbe straight 
alimentary canal. Place in a drop of clean water and 
crush under a coverglass. Note what organisms form 
tbe chief bulk of tbe food. Note tbe presence of sand 
grains, unicellular plants and animals, short lengths 
of alga, diatoms, bacilli, etc. 
Determine tbe common foods of several species 
of Anophelines. 
4. Desiccation of Larvae. —Celli and Casagrandi 
have found that Anopheline larvae can only resist 
desiccation at 20° C. for two days, at 35 0 C. for one 
day, and 40° C. for two minutes only. Larvae of 
Anophelines stranded on moist mud will live as long as 
four days, but in tbe tropics as soon as tbe mud loses 
its glistening surface they die. 
5. Cannibalism of Larvae. — Add some large 
Culex larvae to a small bottle containing some small 
larvae or Anopheline larvae. Tbe Anopheline larvae 
or small Culex larvae will be devoured by tbe large 
forms. Mucidus sp ., C. concolor , and Psorophora sp ., 
are especially cannibalistic. 
6. Observe the occurrence in nature of Culicine 
and Anopheline larvae, also what Culicine larvae are 
found living together. 
7. Fhe Enemies of Larvae. —Add small fish, water- 
beetles ( Dytiscidae , Hydrophilidae ), and their larvae, 
