192 AMERICAN SPIDERS 



bodied moth, its wings spreading nearly two inches, it great eyes 

 shining red in the last rays of reflected light, dips down toward the 

 hunting grounds of the spider. As the insect approaches, Masto- 

 phora gives every evidence of knowing that a prospective victim 

 is near. She moves her body and adjusts her line, as if in tense ex- 

 pectancy. At just the right moment, when the moth comes within 

 the reach of the line, the spider swings it rapidly forward in the 

 direction of the flier. The viscid ball strikes on the underside of a 

 fore wing, and brings the moth to an abrupt stop, tethered by an 

 unyielding line, which will stretch a fifth its length before breaking. 



Fluttering furiously at the sticky end of the lasso, the moth 

 makes every effort to free itself, but the spider is quickly on hand 

 to give the final coup. She bites her victim on some part of its 

 body. With the venomous bite resistance ends quickly; and the 

 paralyzed moth can be rotated and trussed up like a mummy in 

 sheets of silk. Mastophora then sets to work feeding on the body 

 juices of her catch. This bountiful food supply will keep the spider 

 busy for some time. After having satisfied her appetite, she cuts the 

 shrunken remnant loose from the trapeze line and drops it to the 

 ground below. Later in the night a second capture may be made, 

 but Mastophortfs needs for food are usually well met by a single 

 sizable victim. 



It must not be concluded that the life of this spider is quite 

 as simple as the incident portrayed might indicate. Mastophora 

 may wait in vain for a flying creature to come near enough for 

 capture. In many instances, her aim may not be as accurate as pic- 

 tured, or the prospective victim may be too large to be held even 

 by the strong band of silk. But patience is one thing at which 

 spiders excel, and Mastophora is no exception. Should no victim 

 reward her after half an hour of waiting, she winds the globule and 

 line into a ball and eats it. Quickly she spins another line, prepares 

 another sticky bead, and resumes her vigil. 



How wonderfully complex is the pattern of instinctive activities 

 that make up the casting habit of Mastophora! Although endowed 

 with glands that produce silk in copious quantities, the spider bases 

 her whole economy on a blob of sticky silk dangling at the end of 

 a short line. And still not content with a niggardly use of this vital 

 material, she eats the viscid globule if it is not put to use. The 

 trapeze line, the pendulum thread, the viscid globule, and the in- 

 stincts of a hungry spider, have in her combined to produce one of 

 the most sensational of all devices for the capture of prey. 



