AEACHNIDA. 193 



Some species, which always walk straightforward, are 

 called 



Rectigrades (Rectigradd). They weave webs of 

 different kinds, and hence have been divided into 

 different families. 



FlG. 15-i. THE EYES OF SPIDEK. 



The Tube-weavers (Tubiteles), or Tapestry spiders, 

 are celebrated for their ingenuity. The geometric web 

 of the common garden spider (Epeira diadema) has 

 been admired in all ages as a wonderful production, 

 elaborate in its construction, and most effective for 

 its purpose. These nets are composed of two sorts of 

 threads. The framework, which is first formed, con- 

 sists of straight rays diverging from a centre ; these 

 are not adhesive, but over these the spider then 

 travels, weaving a spiral thread round and round, 

 which is the true net ; for this thread, which is more 

 elastic than the other, is studded all over with 

 minute globules of a gummy substance, by which it 

 is rendered tenacious. 



In Rio de Janeiro the family Epeira is characterized 

 by many singular forms. Every path in the forest is 

 barricaded with the strong yellow web of a species said to 

 make nets so strong as to catch birds. A small but pretty 

 kind of spider lives as a parasite upon every one of these 

 webs ; possibly it is too insignificant to be noticed by the 

 great Epeira, and is, therefore, allowed to prey on the 



K 



