THE 



POPULAR SCIENCE 

 MONTHLY. 



APKIL, 1875. 



THE TRIANGLE SPIDEE. 



Br Peof. BURT G. WILDER, 



OF THE COENELL UNIVEESITY. 



STROLLING through the woods near Ithaca, New York, one 

 October afternoon, I saw, upon a leafless hemlock-branch, what 

 looked like a piece of the net of some geometrical spider. Still, there 

 was a regularity in this triangular net which did not accord with the 

 idea of its being a fragment. A closer examination showed that its 

 form and structure were perfect and unbroken ; and moreover that, 

 instead of hanging loosely from the twigs, it was upon the stretch, 

 as if constantly drawn by a power at one or the other end (Fig. 1). 



On touching the net to determine its degree of tension, what was my 

 amazement to see it suddenly loosened with a snap, as if let go at one 

 end ! Nor was my wonder diminished when, a moment afterward, the 

 the net slowly regained its original condition, by a steady pulling upon 

 a short line connected with the apex. And now I saw the puller a 

 little dull-colored spider, about one-eighth of an inch long hanging 

 from the under side of the apex-line, and hauling it in, not "hand over 

 hand," as at first appeared, and as one would suppose by analogy with 

 sailors' operations, but " foot over foot ; " in short, with its hinder legs 

 moved alternately so as to gradually take in that part of the line which 

 intervened between its body and the twig to which it was attached. 



When this line was all taken in, the spider was close against the 

 twig, and its legs were drawn together, so that the whole formed a 

 compact brown mass about the size and shape of a raisin-seed, and 

 differing so little in appearance from the projections of the dried hem- 

 lock-twigs among which the net was built, that I felt in part excused 

 for not having noticed the little creature before. 



So much for an introduction to a spider which was then new to 



me, and probably is still unknown to most of my readers. In some 



respects its habits are unlike those of all our other spiders ; and I will 



here relate what I have learned during five seasons, in the hope that 



vol. vi. 41 



