MOTIONS OF INSECTS. 



269 



the inequalities of the surface on which they repose, so that 

 every joint may in some measure become a point of support. 

 Their eight legs also, which diverge from their body like the 

 spokes from the nave of a wheel, give them equal hold of 

 eight almost equidistant spaces, which, doubtless, is a great 

 stay to them. 



The next species of locomotion exhibited by perfect insects 

 is flying. I am not certain whether under this head I ought 

 to introduce the sailing of spiders in the air ; but as there is 

 no other under which it can be more properly arranged, I 

 shall treat of it here. I shall therefore divide flying in- 

 sects into those that fly without wings, and those that fly 

 with them. 



I dare say you are anxious to be told how any animals can 

 fly without wings, and wish me to begin with them. As an 

 observer of nature, you have often, without doubt, been as- 

 tonished by that sight occasionally noticed in fine days in 

 the autumn, of webs — commonly called gossamer webs — 

 covering the earth and floating in the air; and have fre- 

 quently asked yourself — What are these gossamer webs? 

 Your question has from old times much excited the attention 

 of learned naturalists. It was an old and strange notion that 

 these webs were composed of dew burned by the sun. 



" The fine nets which oft we woven see 



Of scorched dew," 



says Spenser. Another, fellow to it, and equally absurd, 

 was that adopted by a learned man and good natural phi- 

 losopher, and one of the first fellows of the Royal Society, 

 Robert Hooke, the author of Micrographia. " Much re- 

 sembling a cobweb," says he, " or a confused lock of these 

 cylinders, is a certain white substance which, after a fogg, 

 may be observed to fly up and down the air : catching se- 

 veral of these, and examining them with my mycroscope, I 

 found them to be much of the same form, looking most like 

 to a flake of worsted prepared to be spun ; though by what 

 means they should be generated or produced is not easily 

 imagined : they were of the same weight, or very little hea- 

 vier than the air; and "'tis not unlikely but that those great 

 white clouds, that appear all the summer time, may be of the 



