Experiments on Vision. 
247 
against each other, not aware of their proximity to each other 
until in actual contact, when they would turn around very 
quickly. 
A male of Philseus militaris, on being put into a box, at once 
noticed a female that was quietly eating a fly seven inches 
away. He looked at her, raising himself on his first legs to 
see better, and after a moment ran toward her with his palpi 
outstretched. At two inches he threw up his legs and began 
his display. Two males of this species challenged each other 
to battle when standing twelve inches apart, and both males 
and females repeatedly recognized each other at all lesser dis¬ 
tances. 
Dendryphantes capitatus noticed a quiet female eight inches 
away and ran toward her, beginning his display at five inches. 
Icius hartii began his display before the female, showing rec¬ 
ognition of sex, at three inches. 
A male of Zygoballus bettini noticed a female six inches away, 
raising his head and then turning it to see her better as she 
walked around him. 
A male of the little antlike spider Synageles picata, began 
his display before a motionless female when four inches dis¬ 
tant. 
A male of Habrocestum splendens, upon being put into a box 
with a quiet female, became wildly excited, beginning to show 
off like a peacock when five and one-half inches from her. 
In Icius elegans the males and females gave evidence of rec¬ 
ognizing each other at all distances up to seven inches. 
The males and females of Phidippus morsitans showed that 
they recognized each other at all distances up to thirteen inches, 
when quiet or moving slowly. The male danced before a mo¬ 
tionless female at six inches. 
A male of Epiblemum scenicum noticed a female that was 
sucking the juices of a fly seven inches away. He raised him¬ 
self high on his first legs to see her better, and after a moment 
ran toward her with outstretched palpi. 
Phidippus rufus, put into a mating box, seemed to see a fe" 
male seventeen inches away—at any rate he advanced directly 
toward her. At nine inches he showed signs of excitement, 
