FOOD OF INSECTS. 415 



end of this liaie, it did not adhere from mere contact. 

 I therefore twisted it once or twice round the pencil, 

 and then drew it tight. The spider, which had previous- 

 ly climbed to the top of the stick, immediately pulled at 

 it with one of its feet, and, finding it sufficiently tense, 

 crept along it, strengthening it as it proceeded by an- 

 other thread, and thus reached the pencil*. 



That this therefore is one mode by which the geo- 

 metric spiders convey the main line of their nets be- 

 tween distant objects, there can be no doubt, but that 

 it is the only one is not so clear. If the position of 

 the main line be thus determined by the accidental in- 

 fluence of the wind, we might expect to see these nets 

 arranged with great irregularity, and crossing each 

 other in every direction ; yet it is the fact, that however 

 closely crowded they may be, they constantly appear 

 to be placed not by accident but design, commonly 

 running parallel with each other at right angles with 

 the points of support, and never interfering. Another 

 objection too presents itself. From the experiment re- 



* Some time after making this experiment I stumbled upon a passage 

 in Kedi (De Insectis, p. 1 19.) from which it appears that Elancanus, in 

 his Commentaries upon jlnstotle,has relatei a series of observations which 

 led him to precisely the same result. Lehmann, too, in a paper in the 

 Transactions of the Society of Naturalists at Berlin (translated in the Phi- 

 losophical Magazine, xi. 323.) has given an explanation somewhat similar 

 of the operations of this very spider, but T am inclined to think erroneous 

 in some particulars. He describes it as emitting numerous lloatir.g threads 

 at the commencement of ifs descent. That he is mistaken in supposing 

 these threads to be more than one, is proved by the fact which I have 

 observed— that even that one sometimes breaks by the weight of the 

 spider. How then could an insect almost as big as a gooseberry be sup- 

 ported by a line of the tenuity here attributed to it ? 



