FOOD OF INSECTS. 415 



air, and was so light as to be carried about by the slight- 

 est breath. On approaching a pencil to the loose end 

 ot this line, 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 previously 

 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 another 

 thread, and thus reached the pencil*. 



That this therefore is one mode by which the geome- 

 tric spiders convey the main line of their nets between 

 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 influence of the 

 wind, we might expect to see these nets arranged with 

 great irregularity, and crossing each other in every di- 

 rection ; 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 



* Some time after making this experiment I stumbled upon a pass- 

 age in Redi (De Insectis, p. 11 9.) from which it appears that Blan- 

 canus, in his Commentaries upon Aristotle, has related a series of ob- 

 servations 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 Philosophical Magazine, xi. 323.) has given 

 an explanation somewhat similar of the operations of this very spider, 

 but I am inclined to think erroneous in some particulars. He de- 

 scribes it as emitting numerous floating threads at the commencement 

 of its 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 supported by a 

 line of the tenuity here attributed to it ? 



