26 HABITS OP TVOKMS. CHAP. I, 



times a poker heated to dull redness near 

 some worms, at a distance which caused a 

 very sensible degree of warmth in my hand. 

 One of them took no notice ; a second with- 

 drew into its burrow, but not quickly ; the 

 third and fourth much more quickly, and the 

 fifth as quickly as possible. The light from 

 a candle, concentrated by a lens and passing- 

 through a sheet of glass which would intercept 

 most of the heat-rays, generally caused a 

 much more rapid retreat than did the heated 

 poker. Worms are sensitive to a low temper- 

 ature, as may be inferred ' from their not 

 coming out of their burrows during a frost. 



Worms do not possess any sense of hearing. 

 They took not the least notice of the shrill 

 notes from a metal whistle, which was re- 

 peatedly sounded near them ; nor did they 

 of the deepest and loudest tones of a bassoon. 

 They were indifferent to shouts, if care was 

 taken that the breath did not strike them. 

 When placed on a table close to the keys of 

 a piano, which was played as loudly as 

 possible, they remained perfectly quiet. 



Although they are indifferent to undula- 

 tions in the air audible by us, they are 



