1917] Marchand—Notes on the Habits of the Snow-Fly (Chionea) 147 
the place where the snow-covering bordered on the wood of the 
railing, the insect was never seen going on the wood, showing a 
well-marked preference for the snow. Arrived at the end of the 
balcony, the Chionea had to be stopped in order to prevent it from 
falling; this was done by approaching it with the finger, avoiding 
actual contact. This was found sufficient to cause it to change its 
course. If carefully touched with the tip of the finger, it con- 
tracted all the legs towards the body and remained quiet. After 
making two attempts to go in the previous direction, it finally 
turned to the side, and continued to run in a straight line along- 
side the transverse railing of the balcony in the same way as 
described before. 
The fly was then placed in its cage, where it at once started climb- 
ing the glass walls. Shortly afterwards, at 1 p. m., it was again 
found sitting on the underside of the cover, this time under the 
glass plate. At 2.30 p.m., however, it was found to have resumed 
its favorite resting-place, under the wire-cover in its open part, 
at the edge of the anterior glass cover, that is, at the coldest spot. 
On November 26, a very sunny day, observation was omitted in 
the morning. At 2.30 p. m. it was found that the snow in the cage 
was melted and the Chionea was lying motionless in the melting 
water, apparently dead. However, as I knew from my experience 
that drowned caterpillars may often be revived, an attempt was 
made to bring the Chionea back to life and was successful. The 
insect gradually began to move its legs and antenne, until, at 
4.30 p. m., it had regained its normal condition. It was then 
placed back in the cage. 
During the efforts to revive the insect, it was kept in the heated 
room at least part of the time, in order to facilitate the evaporation 
of the water. A piece of blotting-paper was used first to absorb 
the excessive moisture. Blowing seemed to aid it in resuming its 
movements. When these had been started, however feebly, a 
piece of snow was brought to touch the claws of the feet, and it 
was noticed that each time the leg responded with a considerable 
reaction. In fact, snow touching the feet proved to be the strong- 
est stimulus to cause them to move, and I conclude therefore 
that normally the contact of the tarsal claws with the surface of 
the snow is the necessary stimulus for Chionea to keep moving 
continually, as to remain on one place might cause it to freeze. 
