346 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



just above the spider's feet. This is illustrated at Fig. 157, page 167. 

 The same effect is produced by tlie stay lines which are attached above, 

 and which often draw up parts of the surface, as at Fig. 337, into little 

 domes. AVe might almost think of these as the germinal form of the 

 tube as it is seen in the Lineweaving species. But still more distinctly 

 we may see the habit naturally engrafted upon such an interesting species 

 as Theridium zelotypum or Theridium riparium, whose beautiful nesting 

 habits are described in Chapter XVIII. In these species the inside lining 

 of the nest of gathei-ed sticks and rubbish is a distinct tube, which is 

 sometimes prolonged beyond the mouth of its den. 



Indeed, whenever a Theridioid spider takes its place beneath a leaf or 



''■'I'll I f^ 



Fig. 337. Snare of Linyphia costata, showing tent like elevations. 



other shelter, as it often does, especially under stress of continued bad 

 weather, it is sure to spin above and around its abdomen a little 

 a Tube conical mass of lines, which, by the pressure upwards of the an- 

 imal, is compacted or beaten into a concave form. If the weather 

 continue unfavorable, or the spider is undisturbed for a considerable length 

 of time, this little rudimentary tube will gradually make encroachments 

 upon the leafy shelter, and will be prolonged outward and downward. 

 Now, when the sun comes out and invites anew to web spinning, it is in- 

 evitable that the snare will be spun just beneath or close in the neighbor- 

 hood of this tube like shelter. Thus it becomes easy to explain the ap- 

 pearance of a tubemaking habit, not only in Lineweavers, but in Orbweavers 



