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Psyche 
[Vol. 87 
segments of the sticky lines but the water remained fastened to the 
highest point on the line it reached. Hence when the stream 
returned to its normal height, the sticky lines were under excessive 
stress and the water junction failed. 
Web Function and Behavior of the Spider 
Web function. We were never fortunate enough to witness the 
complete natural sequence of prey capture by Wendilgarda spiders. 
However, Figure 4 is a photograph of an insect exuvium which 
floated downstream and contacted one of the sticky lines of a 
Wendilgarda web. The exuvium was dry, and merely resting on the 
surface of the water. It initially touched only one of the sticky lines. 
Apparently the lines adhere preferentially to cuticle in comparison to 
water, because it seemed that on contact the line stuck to the exuvium 
while the sticky line-water junction broke. Fastened to the web by the 
single sticky line, the exuvium oscillated back and forth in the current 
until, in the space of a few seconds, it contacted several other sticky 
lines. At this point we dusted the web to photograph the event. 
Attack behavior. Portions of the attack behavior of Wendilgarda 
spiders can be elicited by vibrating a sticky line or the water next to it 
with a tuning fork. The response of the spider is fairly sterotyped and 
follows one of two patterns. 
1. The spider may move rapidly along the horizontal line to a 
point above the tuning fork and reel in the sticky line until the 
sticky line-water junction breaks. This action involves consider¬ 
able deflection of the horizontal line. The spider then hauls up the 
sticky line and searches the space around the end for a few seconds, 
rolling up the line and turning it over with its first two pairs of legs. 
After a variable length of time, the spiders usually reversed 
direction and returned to the center or periphery of the web. In the 
case where the tuning fork is actually stuck to the sticky line, the 
spider by pulling on the sticky line would pull itself and the 
horizontal line down the entire distance to the water surface. It 
then would palpate the tuning fork with its first two pairs of legs, 
and apparently attempt to bite the tuning fork. 
2. In about half the number of presentations of the tuning fork, 
however, the spider did not simply move along the line toward the 
stimulus. The initial response of the spider was to cut the 
horizontal line at some point fairly close to its connection with the 
