OF THE UNITED STATES 37 



an astronomer, and who had a private observatory near his resi- 

 dence. This gentleman once placed a species of spider in the 

 distant end of the tube or barrel of his telescope, and for several 

 days he unceasingly studied the insect as it created its beautiful 

 web. It was one of those rayed webs made in one plane, and my 

 friend was curious to know if there were either certain^ figures or 

 angles used in its construction in fact, was the spider's net 

 built upon a definite geometrical plan and he came to the con- 

 clusion it was not. His study well repaid him, however, for he 

 acquired a very considerable knowledge of how the spider fas- 

 tened its web together, and the plan it was apparently built upon. 

 Any intelligent observer, by the aid of a lens, can gain a good 

 deal of information about how spiders form their beautiful webs. 

 By holding the insect properly the thread may be drawn out, and, 

 in the common garden spider, for example, it will be seen to issue 

 from a set of very remarkable organs at the under side of the dis- 

 tal extremity of the abdomen. These are called the spinnerets. 

 There may be as many as a half a dozen of these, while at the 

 apex of each there are to be seen upward of a thousand tubulets 

 from which the separate filaments issue. So that the delicate 

 silken thread as it is spun consists of several thousand strands, 

 and it is manufactured in a set of special glands at he base of the 

 spinnerets. At first it is in a fluid form, viscid and tenacious; 

 but when exposed to the air it quickly hardens to form the 

 thread. This last, the spider, by the aid of his hinder pair of feet, 

 fastens to some object, which is easily effected by its adhesive 

 qualities. Then, as he moves away, the thread is formed and 

 drawn out. The manufacture of this material is of the greatest 

 use and importance to these wonderful insects. Some use it to 

 make their webs; some to enshroud their victims captured for 

 food; others to construct trap-doors to various kinds of subter- 

 ranean passages. By means of this thread spiders are allowed 

 to lower themselves down from heights; others float in the air 

 by it; some swing by it across small streams or ditches; and they 

 put it to a variety of other uses. While out in my garden last 

 summer I captured a great, big, dark-brown, hairy spider, that 

 with ease made good headw r ay over the ground, water, lily-pads, 

 and anything on the surface. She carried with her a round ball, 

 double the size of a buck-shot, which, when opened, was found to 

 be filled with hundreds of young spiders. Originally, these were 

 eggs and the mother spun over them this round, silken case. In 



