246 
PecTcham—The Sense of Sight in Spiders. 
A male of Hasarius hoyi was dropped into a box with another 
male, which was standing seven inches away. He at once threw 
up his first legs, this being a challenge to battle. The other 
male responded by throwing up his first legs. The two ad¬ 
vanced upon each other slowly and when only two inches apart 
began to circle about each other, waving their legs. The same 
male when put into the box with a female, saw her as she stood 
quite eleven inches away and at once lifted his first legs, not 
straight up, as in the case of the other male, but obliquely, 
and began to move with a rapid gliding gait, from side to side, 
this being the characteristic display, before the females, in this 
species. At other times we saw the males of this species chal¬ 
lenge each other at two and one-half, at three, at four, at five, 
at six and at six and one-half inches, and saw the males display 
before motionless females at two, five, eight and ten inches. 
The females of this species gave evidence of recognizing males 
which were perfectly quiet, raising the head with a compre¬ 
hensive glance and then turning and running in an opposite 
direction, at four, five, six and eight inches, and one female 
followed with her eyes the movements of a male, as he walked 
about the other end of the box, at least ten inches away. 
A male of Anoka mitrata saw another male which was not 
moving when eight inches away, and at once threw out his 
long plumy first legs. As he takes this attitude both in court¬ 
ship and in fighting, he may not have been able to distinguish 
the sex of the other spider, but he certainly recognized it as 
being of the same species, as he would otherwise have remained 
quite indifferent. 
Another male of this species saw a motionless female nine 
inches away. He raised himself high on the first pair of legs 
and eyed her attentively. After a moment he ran toward her, 
and when four inches away he extended the first pair of legs 
at a right angle to the cephalothorax, and turned his abdomen 
first to one side and then to the other, this being his char¬ 
acteristic display. They frequently saw at from six to eight 
inches when both were standing still, one of them often bend¬ 
ing far to one side to see the other more distinctly. It was a 
common thing for two males, or for a male and a female to back 
