6 Psyche [February 
gers than does the adult. He placed as enemies, first weather 
conditions; then diseases, of which we know little. We have 
seen several conditions which relate to this subject, however. 
Four young larve that had passed their second molting were 
every one of them afflicted with a protruding intestine, which ex- 
tended out from the body for fully half the length of the larva. 
This condition lasted for more than a day after they were taken 
from the pool. A scarcity of food,—for they were kept in clear 
water for twenty-four hours—evidently cured them. They were 
normal on the second day after. 
Spirogyra furnishes food for the growing larva, but it also shel- 
ters enemies. It is the favorite habitat of several species of chi- 
ronomids, and in just so far is it a check to mosquito development. 
The chironomid larve build their tubes of the alge filaments, and 
seemingly of other things too. 
In six different instances we have had evidence that some chi- 
ronomid larvee destroy the larva of Anopheles punctipennis, and 
feed upon its tissues, as well as using portions of its body to fill 
in the crevices of their houses. In all the cases, the Anopheles 
was in the quiescent state just preceding or following the molting 
process. In one case the chironomid built its tube close up beside 
the body of the dead A. punctipennis, and gradually transferred 
the tissues into the walls of its home. In another case a chirono- 
mid was seen to swallow a part of the dark mass of the dead mos- 
quito larva, and the digestion in the chironomid was watched 
through the transparent organs. A healthy larva of A. puncti- 
pennis was supposedly alone in a dish of water with algze for food. 
It was left over night. In the morning its head was torn from 
its body and was floating at a distance. The only living animal 
in the dish was a chironomid larva. 
Development. Careful observations on the swarming of Anoph- 
eles punctipennis have been reported by Knab (1907). The 
males were seen to swarm a little before 5 o’clock of a sunny after- 
noon in October. They came from different directions to form 
the swarm which contained less than a hundred mosquitoes. They 
circled about above a projecting mass of foliage. Mating of a 
number of individuals occurred, and by 5.30 o’clock the swarm 
began to diminsh. 
In the opinion of Kulagin (1907), based upon at least six years 
