36 
closely together at the sides by some gummy secretion, and arranged 
in rows. ‘The mass with Anopheles, however, is laid loosely upon the 
surface of the water, each egg lying upon its side instead of being 
placed upon its end as in the egg mass of Culex. They are not attached 
together except that they naturally float close to each other and there 
are from 40 to 100 eggs in each lot. In Culex pungens the individual 
egg is 0.7 mm. long and 0.16 mm. in diameter at the base. It is 
slender, broader, and blunt at the bottom, slenderer and more pointed 
at the tip. The tip is always dark grayish brown in color, while the 
rest is dirty white. The egg of Anopheles when seen from above is 
of arather regular elliptical outline, the two ends having practically 
the same shape; seen from the side, it is strongly convex below and 
nearly plane above; seen from below, it is dark in color and when 
examined with a high power is seen to be covered with a reticulate 
hexagonal sculpturing. At the sides, in the middle, there appears a 
clasping membrane with many strong transverse wrinkles. Seen from 
above, the egg is black except for a clasping membrane which nearly 
Fig. 12.—Anopheles quadrimaculatus: Newly hatched larva—greatly enlarged (original). 
meets on the middle line in the middle third of the body, but retires to 
the extreme sides for the anterior and posterior thirds. At each end 
the color is lighter, with a group of from 5 to 7 minute dark circular 
spots. It is 0.57 mm. long. Eggs laid April 26 hatched April 30. 
Others laid May 13 and 14 hatched May 16 and 17. 
THe tarva.—The larva is quite as unlike that of Culex pungens as 
is the egg. It differs in structure, in its food habits, and in its cus- 
tomary position so markedly that it can at once be distinguished with 
the utmost ease. The larva of Culex, it will be remembered, comes 
to the surface of the water to breathe, thrusting its breathing tube 
through the surface layer and holding its body at an angle of about 
45 degrees with the surface of the water. While in this position its 
mouth parts are in motion and it is taking into its alimentary canal 
such minute particles as may be in the water at that depth, but these 
are naturally few in number and the larva descends at frequent inter- 
vals toward the bottom to feed. The want of oxygen, however, causes 
it to wriggle up again to the surface at very frequent intervals. Its 
