CONSTRUCTION OF AN ORBWEB. 



67 



traversed in passing from tlie 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 Ijy a rare accident. 

 A large moth, attracted by tlie 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 



Trial Air 

 Lines. 



Fig. 63. Seeking attachment for foundation lines. 



entangled upon some of the short twigs, l)ut never upon the opposite fork, 

 as the wind was steadilj' 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 liy 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 ujjon 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 s^jider exhibited a like behavior. 



4. The third individual, a male, did not attempt to spin an orb in the 

 former site ; the wind was uiifavorable, 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 



