02 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



Founda 

 tions 



Orbweavers who move at once from the beginning of a fuundation to its 

 eompletion as tliough directed by a sure knowledge ; one cannot say by a 

 sure experience, for in point of fact this behavior is not tlie resuU of ex- 

 perience, inasnuich as it is observed in the youngest animals, and on the 

 other hand a(hdts are quite apt to show the confused and indeterminate 

 action above referred to. 



The second mode of securing an orb foundation is by means of air 



currents. It has been questioned by naturalists whether the Orbweaver 



ever piu'sues any other method than that of carrying around the 



f()un(}ation lines. As recently as A. D. 1881, so good an arach- 



ncilogist as Mr. Cambridge expressed the belief that this is the 



Currents "^"=il mode of itroceeding, and that air currents are never 



utilized for the construction of orb foundations. ^ This opinion, 



however, he shortly afterward abandoned, yielding to the facts presented 



,— . ... . ^ . . by other arachnologists.^ 



I have elsewhere treated 

 '•= • tlie question at some 



It'ugth,^ and now present 

 the evidence that the 

 ]irime foundation lines 

 of orb webs are often laid 

 l»y means of air currents. 

 In a great luimber of 

 cases I have ob.served 

 tlic ( ) ill weavers 

 pa.ssing from 

 l)oint to point 

 liy means of lines emitted 

 from their spinnerets and 

 entangled upon adjacent 

 foliage or other objects. 

 Any one who will note with ordinary carefulness the movements of orb- 

 makers among shrubbery towards the close of a fair evening, may see such 

 examples. These mimic "suspension bridges" are of various lengths, owing 

 to the direction of thi^ wind and the jjosition of the spider rclntive to the 

 standing o1)jects around it. Lines of two, three, and four feet are frequent; 

 lines from seven to eight feet occur often ; I have measured one twenty-six 

 feet long, and in several cases have seen lines strung entirely across country 

 roads thirty or forty feet wide.* Many of these lines I have seen carried by 



' Spiders of Dor.set, Rov. O. Pickard-Cambridjrc, Vol. T., Tiitnxluction, pafje 21. 



2 Op. cit.. Vol. II. 



^ Pi-ooeodint.fi Academy Natural Scienc-es of I'liiladelphia, 1881, page 4.S0, Ke(i. — " How 

 Orbwoaviii'.' Sijidei-s make the Framevork or Foundation of Wel)S." 



■* Lister, the father of Kiijrlisli araneology, oliserved sueli lines stretehed hetwiTii trees and 

 over streams. Traetatus .\raneis, pa<<e 8. 



Bridge 

 Lines. 



Fir,, 60. Orbwebs on water plants in a pond. 



