where the fly is, and, finally getting directly above the fly, it gathers 

 its legs for a jump, securing its thread to the window sill at the same 

 time, and then with a sudden spring seizes the fly in its jaws. Some- 

 times the insect is much larger than the spider, and flies away with 

 the spider tightly clinging to it; the thread, however, holds fast, 

 though sometimes run out to the length of a foot or more. Soon the 

 poison of the spider takes effect and the fly gradually weakens and 

 ceases its struggles, when the spider carries it off to some nook, there 

 to devour it. 



One of the most common spider nets is thus made: The spider 

 first runs a few threads as a sort of framework, to which are to be 

 afterward attached the radiating threads, that is, those which run 

 from the center of the net to the sides. Having arranged these so 

 near together that the spider can easily reach from one radiating 

 thread to the other, the creature commences at the center of the 

 net and runs a thread from one radiating thread to the other in a 

 rapidly unwinding spiral till it reaches the outer edge of the net. 

 This is to form a staging and also the better to hold the radiating 

 threads in place. It then commences at the outside and going back 

 over its last course carefully constructs the permanent mesh; and, as 

 it comes to each radiating thread, it will be seen to attach to it the 

 thread it is now making by simply pressing the spinnerets against it. 

 As it goes aroimd again and again, continually lessening the circle, it 

 gathers up the thread which was first laid as a staging, and, rolling 

 it up in little balls, drops it to the ground. This habit has led to the 

 impression that the spider eats its web. The circular threads are glu- 

 tinous, while the radiating threads are smooth, and this can be proved 

 by throwing dust through the net, when the cross-threads will catch 

 and hold the dust, while the radiating threads will remain clean. 

 The actual center of the net is not the geometrical or true center, 

 but a little above it. It may be observed, too, that the net does not 

 stand vertical, but leans a little and the spider having completed the 

 net, takes a position in the actual center of the net, head downward 

 and on the inclining side of the net. With its legs outstretched and 

 resting on the radiating Unes, it can feel the slightest jar or agita- 

 tion made by a struggling insect. The spider being above the true 

 "center of the net and on the inclining side, if the fly has become 

 'entangled below the center, it can instantiy drop to the desired point 

 suspended by the ever-ready thread which it makes, and, swinging to 

 the net, it almost instantly catches the fly. 



k Besides the nets made by spiders to ensnare insects, some species 

 have the power of running out a long thread which answers the pur- 



