98 
Psyche 
[Vol. 87 
Figure 2. A Wendilgarda in fairly fast current, showing the deflection of the 
horizontal line due to the tension in the vertical sticky threads. Photograph taken at 
OTS Finca La Selva. The web has been dusted with cornstarch to heighten contrast. 
the web (e.g., sticky line on left horizontal thread, Fig. lb). 
4. The horizontal line to which a series of sticky lines is attached is 
usually distorted by the tension in the sticky lines. When viewed in 
elevation, the horizontal lines look like a series of straight line 
segments approximating a curve, with the sticky lines connecting 
at the vertices of the angles between the segments (Fig. 2). 
5. If the junctions between the sticky lines and the water surface 
are broken, the horizontal line springs upward to become 
essentially a straight line connecting its endpoints. In a few 
instances some sag in the horizontal line remained, but it was 
always less than before the sticky line-water junctions were severed 
(Figs. 3a, 3b). 
6. One can clearly see the elastic response of the web to variation 
in the height and flow rate of the stream (Fig. 2). The stream height 
fluctuated naturally about +5 mm, and in highly tensed webs even 
this increase in tension was occasionally sufficient to “pop” some 
of the sticky lines free of the water surface. 
7. Webs also popped if subjected to moderate-sized waves. In this 
case the leading edge of the wave apparently washed over the lower 
