Other Invertebrate-Animal Study 



479 



heres to any object brought in contact with it. An insect which touches 

 one of these spirals and tries to escape, becomes entangled in the neighbor- 

 ing lines and is thus held fast until the spider can reach it. If one of these 

 elastic lines be examined with a microscope, it is a most beautiful object. 

 There are strung upon it, like pearls, little drops of sticky fluid, which 

 render it not only elastic but adhesive. 



vSome species of orb- weavers remain at the center of the web, while 

 others hide in some little retreat near at hand. If in the middle, the 



spider always keeps watchful claws upon 

 the radii of the web so that if there is any 

 jarring of the structure by an entrapped 

 insect, it is at once apprised of the fact; if 

 the spider is in a den at one side, it keeps 

 a claw upon a trap line which is stretched 

 tightly from the hub of the web to the den, 

 and thus communicates any vibration of 

 the web to the hidden sentinel. When 

 the insect becomes entangled, the spider 

 rushes out and envelops it in a band of silk, 

 which feat it accomplishes, by turning the 

 insect over and over rapidly, meanwhile 

 spinning a broad, silken band which 

 swathes it. It may bite the insect before it 

 begins to swathe it in silk, or afterwards. 

 It usually hangs the swathed insect to the 

 web near where it was caught, until ready 

 to eat it; it then takes the prey to the 

 center of the web, if there is where the 

 spider usually sits, or to its den at one side, 

 if it is a den-making species, and there 

 sucks the insect's blood, carefully throwing 

 away the hard parts. 



The spider does not become entangled 

 in the web, because, when it runs it steps 

 upon the dry radii and not upon the sticky 

 spiral lines. During the busy season, the 

 spider is likely to make a new web every 

 twenty-four hours, but this depends largely 

 upon whether the web has meanwhile been 

 destroyed by large insects. 



The spider's method of making its first 

 bridge is to place itself upon some high 

 point and, lifting its abdomen in the 

 air, to spin out on the breeze a thread 



of silk. When this touches any object, it adheres, and the spider 

 draws in the slack until the line is "taut;" it then travels across 

 this bridge, which is to support its web, and makes it stronger by doubling 

 the line. From this line, it stretches other lines by fastening a thread to 

 one point, and then walking along to some other point, spinning the thread 

 as it goes and holding the line clear of the object on which it is walking by 

 means of one of its hind legs. When the right point is reached, it pulls 

 the line tight, fastens it, and then, in a similar fashion, proceeds to make 



.-1 dcwv morning. 



Insect Life, Comstock. 



