SPIDERS AND MITES. 211 



and occasionally throw out adhesive threads to entrap 

 their prey. The Latebricolce lijde in burrows and fissures, 

 which they line with a web. The Tubicolce inclose them- 

 selves in a silken tube, strengthened externally by leaves 

 or other foreign substances. The XiditeJce weave a nest, 

 whence issue threads to entrap their prey. The Filitelcp, 

 are remarkable for the long threads of silk which they 

 spread about in the places where they prowl in quest of 

 prey. The Lapitelce spin great webs of a close texture, 

 like hammocks, and wait for the insects that may be 

 entangled therein. The Orbitelce spread abroad webs 

 of a regular and open texture, either circular or spiral, 

 and remain in the middle or on one side, in readiness to 

 spring upon an entangled insect. The RetiteliP spin webs 

 of an open mesh- work, and of an irregular form, and 

 remain in the middle or on one side, to seize their prey. 

 Lastly, the Aquitelce spread their silken filaments under 

 water, to entrap aquatic insects. 



" The silken secretion of Spiders is not applied only to 

 the formation of a warm and comfortable dwelling for 

 themselves, or of a trap for their prey ; it is often em- 

 ployed to master the struggles of a resisting insect, which 

 is bound round by an extemporary filament, spun for the 

 occasion, as by a strong cord. It forms the aeronautic 

 filament of the young migratory brood. It serves to 

 attach the moulting Hydrachna to an aquatic plant by 

 the anterior part of the body, when it struggles to with- 

 draw itself from its exuvium. Lastlv, a softer and more 

 silken kind of web is prepared for the purpose of re- 

 ceiving the eggs, and to serve as a nest for the young." * 



The silk with which these various fabrics are con- 

 structed is a thick, viscous, transparent liquid, much like 

 a solution of gum arabic, which hardens quickly on expo- 

 sure to the air, but can meanwhile be drawn out into 

 thread. So far, it agrees with the silk of the silkworm 

 * Owen, "Comp. Anat." (Ed. 2), 458. 



p 2 



