218 AMERICAN SPIDERS 



lurking spider races swiftly and surely to the site of the disturbance. 

 Agelena wastes little time on small insects, seizing them quickly, 

 but bulkier prey is approached with more caution. She rushes in to 

 deliver quick bites, then retreats until the weakened insect can be 

 approached and dragged into the funnel retreat for feeding. Many 

 kinds of insects come her way, but the abundant grasshopper popu- 

 lation of the grassland probably provides her with the highest per- 

 centage of her food. 



The female grass spider lays her eggs in the fall and dies some 

 time thereafter, her whole life spanning only a single year. The sac 

 is a lens-shaped packet composed of two circular valves sewed to- 

 gether around the edges, and is similar in form to those of the crab 

 spiders and many others. Several sacs may be made. All are hidden 

 in secluded places, frequently under the loose bark of trees. They 

 are fastened closely to the substratum, and covered with silk in 

 which bits of bark and debris are distributed, but this stratagem 

 does not deter parasitic insects from laying their eggs in the masses. 

 Investigation of the sacs, even in the late autumn when the female 

 is still very much alive and should be able to protect her young, 

 will often disclose that the contents have already provided food for 

 parasites that now occupy the cradle. 



The nets of the cellar spiders and other agelenids are the same 

 cobwebs used so extensively many years ago by European peasants 

 to staunch the flow of blood. When several of these clean sheets are 

 superimposed, they form a fine transparent fabric, which has some- 

 times been used as a canvas by artists. Most of the paintings on 

 spider silk were done by an Innsbruck family named Burgman early 

 in the nineteenth century, and some may be found in American 

 collections. Delicately done, remarkably durable in spite of the 

 nebulous canvas, they are exquisite examples of an art that now 

 ranks as scarcely more than a curiosity. 



THE JUMPING SPIDERS 



The line of two-clawed vagrants culminates in the jumping 

 spiders of the family Salticidae (see Plates 30, 31, and 32; Plates 

 XXXI and XXXII). These are specialists. They stalk and attack 

 insects with a precision and alertness not possible for myopic types. 

 They are big-eyed experts that hunt during the daytime, and far 

 outshine the wolf spiders and their kin. Their life in the sun seems 

 to have produced a variety and brilliance of coloration not matched 



