June, I904 ] DyAR : LiFE HiSTORY OF CULEX VARIPALPUS. 91 



attached as are those of C. atropalpiis. They hibernate either dry or 

 \vet according to the condition of the environment. Immediately on 

 the thawing of the ice in spring many of the eggs hatch, but others 

 hatch later and irregularly so, some not developing for a month or 

 more after the first ones. Consequently larvae of various sizes occur 

 in the same position till late in the season. The growth of the larvae 

 is slow. Their long anal processes supplied with tracheae enable them 

 to remain long under the water and, when disturbed, they will wriggle 

 at the bottom of the dish with a continuous, rather slow, serpentine 

 motion for longer than one has the patience to watch them. I have 

 occasionally observed them in the breathing position. The food seems 

 to consist of various decaying matters. Of insect remains they seem 

 especially fond. A dead fly was introduced into the jar and, after it 

 had become well moulded, the larvse could be seen in a dense cluster 

 about it, apparently biting and tugging and struggling to get at the 

 object. I do not know exactly what sort of natural breeding places 

 the larvae frequent. My colony came from a tin vessel in an aban- 

 doned hut. From these I bred adults which deposited eggs that passed 

 the winter and hatched the following spring as I have described. 



The egg (Plate III, Fig. i) is fusiform, one end more tapered 

 than the other, one side flattened. It is very small, being .5 mm. 

 long and .2 mm. wide. Deep black in color with peculiar sculptur- 

 ing, reticulate in elongate ellipses like craters, all spicular granular 

 shagreened. 



In the first stage (Plate III, Fig. 2) the larvae are small, colorless 

 whitish, the harder parts scarcely at all infuscated. The head is 

 rounded and rather long, flattened, normal, the antennae moderate, 

 uniform with a slight hair at the middle. Eyes small and weak, but 

 transverse. The body has the usual flattened globose thorax and sub- 

 moniliform abdominal segments. The prothoracic hairs are shorter 

 than the others. Air tube about three times as long as wide, very 

 slightly inflated, weakly infuscated at the tip ; a weak pecten followed 

 by a hair. Lateral comb of the eighth segment of a few spines 

 (Plate III, Fig. 3) in a single row, weak and illy defined. Anal seg- 

 ment without perceptible plate, a dorsal posterior tuft and single hair 

 on each side but no ventral brush. Anal processes not large but 

 cylindrical, rounded and tracheate. 



The second, third and fourth stages are essentially alike. The 

 ventral brush is acquired (Plate III, Fig. 4), but it does not arise from 



