8 Psyche [February 
from the first. With these it sweeps in any small particles in 
the surface film. It takes but a short time to exhaust the immedi- 
ate supply, and so the larva moves from place to place. Fre- 
quently it bends and brushes over its whole body as far as it can 
reach, removing anything like vorticelle or diatoms. Sometimes 
these develop too rapidly and it is not at all uncommon to find 
larve less than three days old, thickly fringed with these sessile 
forms. Of course, such as attach themselves to the head and 
anterior part of the thorax remain there, being out of range of the 
jaws. 
If food particles are scarce, the larva will brush over any alge 
or other plants that may be at the surface. One very small larva 
was seen to remain down below the surface film for about half a 
minute in search of food. One of these very young ones was seen 
to eat a short filament of fine Spirogyra, when the larva was less 
than two days old. It refused a row of diatoms. It started back 
from an on-coming rotifer immediately in front of it. The same 
rotifer ran into and over the long anterior bristles from the thorax 
and the young larva gave no response. But when it happened 
again from the front, the larva darted away. The most con- 
spicuous movement of an Anopheles larva of any age is its turning 
of the head through an angle of 180 degrees, when feeding. The 
young larva does this with energy whenever feeding on surface 
particles. It turns the head always in the same direction—counter- 
clock-wise, as was determined by the periodical disappearance of 
a Vorticella which was attached to the side of the head. This 
always moved downward and out of sight before appearing at — 
the other side. 
The young larva measures from .7 mm. to .8 mm. in length, 
not including the hairs at either end of the body. The second 
and third segments of the thorax have not yet united and the head 
is very prominent. The dorsal surface is dark brown in color, 
except where there are conspicuous yellow spots, which are caused 
by the cenocytes within. On the segments of the thorax and on 
five of the segments of the abdomen these yellow spots are very 
noticeable, especially on the third segment of the abdomen. The 
head is colored an even gray, with a dark spot in the center, and 
one small spot on each side. The single eyes and “collar” are 
reddish in color and remain so during the first day. The branched 
