STRUCTURE OF WEB 183 



attached a ball of clay about the size of a 

 small marble. The clay ball was literally 

 wrapped up in web material. Its use was 

 obvious. When the web was blown one way 

 the plumb pulled in the opposite direction, and 

 so the snare was kept comparatively steady. 

 It was a success it withstood the storm ! 



Blackwall, the great authority of the past 

 generation on spiders, states that two different 

 kinds of materials are used in the construction 

 of their nets. The boundary lines, the radii 

 and the first-formed spirals are unadhesive, and 

 possess only a moderate share of elasticity ; they 

 are evidently composed of a different material 

 from that used in making the spiral line which 

 completes the web, which is exceedingly viscid 

 and elastic in a remarkable degree. The 

 viscidity of the spiral thread may be shown 

 to depend entirely upon the presence of a series 

 of globules, resembling tiny beads ; if these 

 be removed, a fine glossy line is left which is 

 highly elastic but perfectly unadhesive. 



Dr. Dallinger tells us that these beads, or 

 globules, are produced after the thread is drawn 



