to escape from an isolated Situation. 425 



residing in Switzerland, and which will place the matter be- 

 yond a doubt, in as far, at least, as it relates to one of the 

 species, though not with respect to the Aranea domestica, or 

 common house spider. 



While residing on the shores of the Lake of Thoun, in the 

 summer of 1828, I was frequently in the habit of spending 

 some hours on the water, in a small boat, near a low part of 

 the shore, where there was abundance of reeds growing in 

 the water, and where those reeds gradually became more 

 widely scattered, as the depth of the water increased, until at 

 length they entirely disappeared. 



I had frequently had occasion to remark, amongst the thick- 

 er crop of reeds, the singular manner in which the tops and 

 stems of the plants were bound together by cobwebs of such 

 strength and elasticity as to resist the action of the most 

 powerful winds. But having observed that even the most di- 

 stant and completely isolated plants were equally furnished 

 with spiders and cobwebs, it became an intei-esting inquiry 

 how the communication with these more distant objects was 

 brought about, and what means of escape the Utile colonists 

 had within their power; as I had never observed an instance 

 of their passing along the surface of the water. 



On taking, therefore, one of these spiders in my hand, I 

 was not long in discovering their mode of operation. For 

 when placed on the point of my fingt-r, in an elevated po- 

 sition, I observed that a fine thread was proceeding in a ra- 

 pid course, from the loom, and was carried by the wind to 

 leeward, where it became attached to the first object witli 

 which it came in contact; and a communication was thus ef- 

 fected, by means of which the little captive was not long in 

 making his escape. 



Having thus discovered their general mode of operation, 

 1 had subsequently many opportunities of amusing myself 

 and my friends, by more particular remarks and experiments 

 on the powers of these curious insects. I have more than 

 once taken spiders out into the lake, to endeavour to ascertain 

 to what length this projected thread might be extended. In 

 these experiments, tried in situations where a dark shade, as 

 a back ground, enabled me to follow the course of the thread 

 with my eye to some distance, it was always carried in about 

 half a minute beyond my powers of vision, or to a distance of 

 about twenty-five or thirty yards; and as no object intervened 

 to which it could become attachet!, 1 have reason to think it 

 might extend considerably further. On one occasion, I was 

 enabled distinctly to trace the whole process, and the eventual 

 escape of the spider to an object fully twenty yards distant. 

 Third Series. Vol. 1. No. 6. Dec. 1832. 3 I 



