(it) AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



and moimtaius. (See Fig. 02.) This liabil is not limitt-il tu AiiR'rieau 

 sj)iilers. \'insoni says that in Madagascar Epeira (Nephila) tuberculosa 



throws from one bank to tlio other of streams of considerable size 

 Cobweb j^^^j. jjj^gj^ Qf prodigous length, in which are arrested numbers 



of Libelluliu and large Agrions. He liad observed this phenom- 

 enon uiKiu running stresims of forest interiors. One might call them, in 

 trutli, aerial l)ridgcs. In the island of Reunion it is to tlie wrinkled trunks 

 of tlie huge I'andanus that the gigantic Orbweavers attach their long silken 

 lines, and stretch them from one tree to another at a distance of man}' 

 metres. 



3. I have greatly desired, but heretofore without conij»lete success, that 

 to the above cases of circumstantial evidence might be added actual ob- 

 servations of the use for foundations of lines stretched by air currents. 

 Three sunnner evenings were once entirely devoted to endeavors to obtain 

 this result. On one evening I was interrupted and called off at a very 

 critical period of my observation ; on the two other evenings the wind was 

 mifavorable ; but some valuable results were obtained. The webs of three 

 adult individuals of Epeira strix, one male and two females, were selected, 

 the den or nest of each spider located, and the web entirely destroyed. 



The latter precaution was made Jiecessary by the fact that Orb- 



'^.^°^'^' weavers use the same foundation lines during many succes- 



„ J sive days for the erection of their new webs. The great value 



Preserved . -^ , . ... 



wliich may attach to tliese old foundations apj>eared strikingly in 



subsequent .studies, and also the ditticulty if not impossibility of procuring 

 suitable foundations for the webs of large spiders without the aid of the 

 wind. In fact, a good foundation frame is a "good property," and it is ac- 

 cordingly treasured and used as long as it remains. I have noted many 

 cases of snares continuing on the same site as long as the foundation lines 

 endure. Their destruction is generally followed by a shifting of position. 



Two of the above webs (one of the females) were so situated that the 

 prevailing air currents carried tlie lines in such wise that they could not 

 possibly tind entanglement. In consequence neither of tliese 

 spiders succeeded, during two entire evenings up to half-past ten 

 o'clock, in making a web. They fre(piently attempted it in vain. One 

 spider that was more clo.sely watched, was in motion during the whole 

 ])eriod, passing up and down, from limb to limb, apparently desirous of 

 fixing her web in its former site, but completely confused and foiled. Tlie 

 site was one, moreover, which would have allowed her to carry around a 

 thread with comparative ease, being a dead sajiling tliat forked near the 

 ground. 



This spider domiciled during the day on the ground, but had her orb 

 at the top of the forks, a height of six feet. Thus the space to be 



' Araneides des les Isles La Reunion, &c., page XIX. 



