244 
PecJcham—The Sense of Sight in Spiders. 
A tiny black fly approached to within two inches of a male of 
Habrocestum splendens. The spider advanced very slowly fac¬ 
ing the fly, which seemed to be fascinated, gazing into the 
spider’s eyes, but backed slowly away moving its abdomen up 
and down in a peculiar manner. They moved along in this way 
for two and one half inches, when a gnat flying by, distracted 
the attention of the spider. 
Again, a hungry male of this species was put into a box where 
there were several small flies. He at once began to stalk a 
motionless fly which was standing five inches away, but lost it. 
He then fixed his attention upon another fly four inches away 
but before he approached it the fly began to move and walked 
slowly away from him around the corner of the box and then up 
on to the glass cover. The spider followed the fly with his eyes, 
moving his head around to keep it in view. The same spider 
afterward stalked a fly which was standing quiet three inches 
from him. 
A female of splendens, being dropped into a box, at once saw 
a motionless gnat full four inches away, lifting her head and 
drawing her legs together as she approached it. Another fe¬ 
male of the same species noticed motionless gnats fifteen differ¬ 
ent times at distances of from two to five inches. 
A female of Epiblemum scenicum being put into a box con¬ 
taining flies lifted her head and drew herself together on see- 
a motionless gnat five inches away. This was repeated with a 
fly at three and one-half inches. 
A male of Anoka mitrata followed a moving gnat at dis¬ 
tances of two, of four and of six inches. 
A male of Phidippus rufus, standing in a corner of his box 
turned around and brought into view a small green grasshopper 
which was standing quiet two and one-half inches away. He 
at once began to creep forward as they do when approaching 
prey and soon seized it. There can be no doubt that he saw it 
at once. He had before made several half-hearted moves toward 
some small flies which were walking about from one-quarter to 
one-half an inch from him, but only when they actually intruded 
themselves upon him. At another time this spider saw a mo¬ 
tionless grasshopper three and one-half inches away and jumped 
