218 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



Special 

 Adapta 

 tion. 



special exigencies. Most of the above examples and perhaps all are illus- 

 trations of this. Another case in point was furnished by a Shamrock 



spider, Epeira trifolium, that 

 exhibited a remarkable ability 

 to adapt her domi- 

 cile to very peculiar 

 circumstances. She 

 had placed her nest 

 in the curled leaf of a grape 

 vine, which becoming detached 

 from the stem fell and entan- 

 gled within the lines of the orb 

 beneath. Whereupon the oc- 

 cupant, in nowise disconcerted, 

 adjusted her tent, stayed it 

 above and at the sides with 

 guy lines, braced it beneath, 



Fig. 205. Furrow spider's extemporized den of sawdust. 



and proceeded to spin her snare directly 

 below the opening. She attached her trap- 

 line to the hub, and thus in her hanging 

 home continued to wait for prey.^ (Fig- 

 204, page 216.) 



Another somewhat similar case of adap- 

 tation in nest making was due to an acci- 

 dent in the environment of the web. A 

 half-grown Epeira strix had wov- 

 en a snare in the hollow of a tree 

 (at New Lisbon, Ohio), within two 

 feet of the ground. A colony of Pennsyl- 

 vania carpenter ants (Camponotus Penn- 

 sylvanicus) had quarters in the tree, and a 

 squad of black workers were busy excavat- 

 ing their wooden galleries. These dumped 

 their chippings from openings just above 

 the spider's orb, whose viscid spirals re- 

 tained a goodly quantity of the brown 

 sawdust. In course of time a ball of chip- 

 pings as big as a walnut had accumulated, 



A Saw- 

 dust Nest. 



Fig. 206. A blockaded path. 



' The incident occurred at Vineland, New Jersey, and uotcH and measurements for the 

 figure were fnrnislied me by Mrs. Treat. The incident is also recorded in that author's 

 "My Garden Pets." 



