230 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



Again, it is obvious that in cases where an Orb weaver is dependent upon 

 the wind to carry her foundation lines from the starting point to a point 

 of attachment, the length of that line will necessarily be deter- 



Modified 

 by Wind. 



mined by circumstances. TJie cord may float off a goodly dis- 

 tance before striking an object, or may entangle soon. In the 

 latter case, as the foundation line will be limited, the snare will be dimin- 

 ished accordingly. I have known a Furrow spider to make a web a 

 foot wide one night, and the next night, when becalmed and prevented 

 from stretching a foundation in her old site, spin an orb four inches in 

 diameter. 



Young spiders make small webs, and invariably very perfect ones. The 

 irregular, abridged, or patched snares which one sometimes sees, when not 



Fig. 217. Typical orbwebs, Epeira strix. 



the result of wear and tear, are those of adults ; never, I believe, of young 

 Orbwcavers. 



The following are a few measurements of the orbs of some of our com- 

 mon species. Epeira insularis : inches, six by six; thirteen by eleven; four- 

 teen by fourteen ; twenty by fourteen ; fourteen by fourteen. Epeira strix : 

 two by one and one-half; twelve by eight; nine and seven-eighths by nine 

 and one-half. These are measurements of the orb alone, not including the 

 foundation spaces. It will be seen that only a part of the above orbs are 

 nearly circular ; more frequently, perhaps, they are somewhat elliptical, the 

 vertical diameter being the longer. The central space occupies about one- 

 third or from one-third to one-fourth of the orb, the spiral space on either 

 side about equaling it in width. The hub ai)proximates the geographical 



