SENSE OF TOUCH. V 7 



selves must also have this sense in perfection ; for in 

 making the various rays as well as the cross lines of 

 a geometric net, the spider always guides the thread 

 from the spinneret by one of its hind claws, which 

 it cannot possibly see with any one of its eyes, as 

 these are all placed forwards on the head. The ex- 

 quisite workmanship of these webs, thus woven as it 

 were in the dark, indicates that the sense of touch 

 by which alone it can be accomplished must be pecu- 

 liarly delicate. 



In the family of the harvest spiders (Phalan- 

 gioidce), which have only two eyes, and do not 

 spin webs, the long legs are used not only to escape 

 from enemies and pursue prey, but to explore, by 

 touch, the objects among which they travel. That 

 the very long legs of these insects are endowed with 

 much nervous power, appears from their continuing to 

 move for many hours after being accidentally detached 

 from the body *, a circumstance which we have fre- 

 quently witnessed with wonder, and which could not 

 well occur if these creatures possessed a brain. On 

 the other hand, most beetles, it is probable, and the 

 various moths, make little use of their feet to explore 

 the things around them. There are many other 

 insects, however, which seem to have feet little less 

 exquisitely formed, as organs of touch, than the 

 human hand, if softness and elasticity be taken as 

 the standards of comparison. 



The insects to which we allude are those which 

 live among grass and herbage, comprehending a few 

 beetles (Chrysomelidce, 4*c.), most two-winged flies 

 (Diptera), and, if we mistake not, all the crickets and 

 grasshoppers (Gryllidcd^ <rc.) The foot of the com- 

 mon fly has been shown by Sir Everard Home and 

 Mr. Bauer to be admirably adapted for climbing upon 



* Latreille, Monographic des Faucheurs, Hist, des Fourmis, 

 page 371. 



