ARGONAUT ANT) GEOMRTFAl. 



218 



FIG. To. — ALTEKNATE APPOSITION. 



You observe that 

 there was a con- 

 tinual altei'nation 

 of the lines, and 

 for the most part 

 a double alterna- 

 tion — t hat is, 

 they were op- 

 posed to each 

 other not only as 

 to the sides — 

 right and left— 

 but as to the top 

 and bottom. You 

 can all see that 

 this order kept 



the web equally braced and well trimmed from the be- 

 ginning to the end of the work." 



" I see that very clearly," remarked Abby, "although 

 I confess that I have little taste for mechanics. But 

 that isn't all of the web, is it ? Where are the little 

 ladders that run up and down from the center ? 

 You pointed them out to me in the snares of Bank 

 Argiope and Caudata. Besides, I remember them by 

 some of my experience in broidery, as this kind of 

 snare has been very popular in fancy needle-work." 



"The 'ladders,' as you call them, the spider makes 

 immediately after the radii, and there is proof of good 

 engineering in this part of her work also. When the 

 radii are quite done she braces them around the ends, 



