Mr. W. W. Saunders on a Spider's Tfeh. 129 



detailed in the paper before referred to. The raising of the pebble 

 to the height of a foot and a half, as observed by myself, and far 

 higher according to Mr. Spence's observations, is certainly a great 

 and wonderful work for a spider, and disjolays its strength and inge- 

 nuity. I am not aware of the weight of a full-grown Epeira dia- 

 dema, but it must be very much less than six grains, the weight I 

 have ascertained it raises, and therefore the means employed to raise 

 so great a weight in proportion to itself, must be an interesting mat- 

 ter of inquiry, but is involved in many difficulties. I think the 

 pebble must be raised by some ingenious means which the spider 

 possesses of shortening the lower cable of attachment, as diminish- 

 ing the length of any of the upper part of the web could never 

 raise the pebble to the height it has been observed to be raised. 

 Allowing this to be the case, the lifting of the pebble can be ac- 

 counted for thus : The spider in having unintentionally fixed its 

 lower point of attachment to a small loose pebble, may detect that 

 it is unsteady, and pulling at the cable to tighten it, probably raises 

 the pebble off the ground, and so continuing its efforts to remedy a 

 defect, at last desists, finding the task impossible, and the pebble 

 remains suspended in the air. This is of course a mere supposition, 

 and the spider, to accomplish it, must have very great strength, — 

 greater, perhaps, than many will allow. A fact, however, pointed 

 out to me by Mr. Westwood in No. xii. page 454, of the Edinburgh 

 Journal of Natural and Geographical Science, proves that spiders have 

 great strength, and display considerable ingenuity in raising weights. 

 The fact is related by the Rev. W. Turner ; and he states, that a 

 sprig of Laurastinus being put into a tumbler with an Aranea ex- 

 tensa ?, the latter raised it up into the tumbler, and kept it suspended 

 there by means of lines of web. Here, certainly, the difficulty does 

 not appear to have been so great as in the raising of a small pebble 

 by a single line ; however, as it tends to illustrate the strength and 

 ingenuity of spiders, I have mentioned it. The contents of the pre- 

 sent paper appear so insignificant, that I should not have thought 

 of troubling the Society with them, had not I wished to gain infor- 

 mation on the subject from some of the experienced entomologists 

 who are members of it, and who will perhaps give much valuable 

 information on the subject. 



