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62 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
Orbweavers who move at once from the beginning of a foundation to its 
completion as though directed by a sure knowledge; one cannot say by a 
sure experience, for in point of fact this behavior is not the result of ex- 
perience, inasmuch as it is observed in the youngest animals, and on the 
other hand adults 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 pursues any other method than that of carrying around the 
Founda- foundation lines. As recently as A. D. 1881, so good an arach- 
ae nologist as Mr. Cambridge expressed the belief that this is the 
Currents, Usual mode of proceeding, 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 
the question at some 
length,? and now present 
the evidence that the 
prime foundation lines 
of orbwebs are often laid 
by means of air currents. 
In a great number of 
cases I have observed 
the Orbweavers 
passing from 
point to point 
by 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 the wind and the position of the spider relative to the 
standing objects 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 
Bridge 
Lines. 
Fic. 60. Orbwebs on water plants in a pond. 
1 Spiders of Dorset, Rey. O. Pickard- -Cambridge, Vol. L, Introduction, page 21. 
2 Op. cit., Vol. ID. 
* Proceedings Academy Natural Sciences of Philadelphia, 1881, page 430, seq.—‘ How 
Orbweaving Spiders make the Framework or Foundation of Webs.’ 
* Lister, the father of English araneology, observed such lines stretched between trees and 
over streams. Tractatus Araneis, page 8. 
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