CONSTRUCTION OF AN ORBWEB. 67 
traversed in passing from the top of one of the forks to a similar point on 
the opposite one, presented comparatively few difficulties. But no attempt was 
made to carry the line around, and as the wind had evidently not changed 
during the night, no web appeared on the tree in the morning. During 
the next evening the same restless movement along the bare limbs of the 
sapling was repeated, and was terminated at a late hour by a rare accident. 
A large moth, attracted by the lantern, became entangled upon a single 
short thread strung between two small twigs, whereupon Strix pounced 
upon it, swathed and fell to feeding on it. Next morning a tiny orbweb 
had been built around the shell of the moth at the point of capture. 
During both evenings this spider at frequent intervals poised herself 
at the extremity of twigs, and emitted threads from her spinnerets which 
Fic. 63. Seeking attachment for foundation lines. 
entangled upon some of the short twigs, but never upon the opposite fork, 
as the wind was steadily contrary. No other entanglement was 
secured, as there was no elevated object in the direction of the 
wind for a great distance. However, I could at any time obtain 
an entanglement upon my hand by arresting the thread. By imitating 
the motion of a swaying leaf or limb, the spider was caused to perceive the 
attachment, and immediately ventured upon the line. (See Fig. 63.) Once 
the thread fastened upon my face, and the animal was allowed to cross the 
line, a distance of four or five feet, until within a few inches of the face, 
when she took in the situation, instantly cut the line and swung downward 
and backward over the long arc, and, after a few oscillations, climbed up 
the line to the point of departure. Her willingness to use air currents for 
making transit lines was thus quite as manifest as her then inability to 
get a foundation thereby. The second spider exhibited a like behavior. 
4, The third individual, a male, did not attempt to spin an orb in the 
former site; the wind was unfayorable, but there would not have been 
much difficulty in carrying the cord around. He came out of his rolled 
leaf den at 7.20 P. M., and for more than an hour labored to secure a web 
foundation. He was located upon a dead end of a bough with many 
Trial Air 
Lines. 
