THE TRIANGLE SPIDER. 



645 



2. How is the Net made ? Like most geometrical spiders 

 (Jjpeiriclce), the Hyptiotes prefers to construct her net just before day. 

 She is then less liable to interruption, and the newly-made net is best 

 adapted for use in taking the builder's breakfast. To these early 

 hab.Us on the part of the spider is owing the fact that, although I 

 have kept many of them in the house, I have never yet been so fortu- 

 nate as to witness the entire process of net-making. Twice I sat up 

 all night, but the spiders must have begun just as I fell asleep shortly 

 before day ; and my readers will understand that, in the midst of the 

 fall term, a professor does not often feel able to spend a night in 

 watching spiders. 



However, I have twice witnessed the completion of nets, and have 

 seen enough of the process to enable me, aided by what is known of 

 spiders' methods in general, to infer how the net is begun and carried 

 on, and the correctness of the following description may be accepted 

 as at least probable, until disproved by actual observation of the 

 entire process : 



i 



Fig. 5. a, last two segment? of the hinder (fourth) lee; of a female Hyptiotes ; b, tip of the last 

 segment, showing- the claws open ; c, cross-section of the last segment but one, showing its 

 cavity, in which iie the muscles, and a single curved bristle upon the side, a part of the 

 calamistmm; e, a similar bristle still more enlarged; d, f, two feathered bristles from near 

 the joints. 



Having first decided upon the general location of her net, the 

 spider probably takes position head downward upon the "leeward" 

 side of a twig or small branch, or upon its top, and then, turning her 

 abdomen outward, expresses from her spinners a drop of gum, which 

 instantly dries so as to form a fine end of a silken thread. This is 

 taken by the wind (and careful experiments have proved that a 

 current of air is absolutely necessary to the extension of the line) and 

 wafted outward, waving from side to side, and usually tending up- 

 ward from its extreme lightness, until at last it touches some other 

 branch at a greater or less distance from the first. When this stoppage 

 is perceived by the spider, she turns about and pulls in the slack line, 

 until she is sure that the other end is fast. If it yields, she tries 



