THE INSTINCT OF SPIDERS 137 



instinct is fully satisfied. It cannot for an instant con- 

 template its handiwork and witness the utter ruin. 

 Reconstruction now is impossible. Another day must 

 pass before the instinctive fire rekindles and the spider 

 feels the call to work. 



I recalled in these connections the ingenious and 

 oft-described experiment of P. Huber. He discovered 

 a caterpillar which made " by a succession of processes 

 a very complicated hammock for its metamorphosis ; 

 and he found that if he took a caterpillar which had 

 completed its hammock up to, say, the sixth stage of 

 construction, and put it into a hammock completed up 

 only to the third stage, the caterpillar did not seem 

 puzzled, but repeated the fourth, fifth and sixth stages 

 of construction. If, however, a caterpillar was taken 

 out of a hammock made up, for instance, to the third 

 stage, and put into one finished to the ninth stage, so 

 that much of its work was done for it, far from feeling 

 the benefit of this, it was much embarrassed, and even 

 forced to go over the already finished work, starting 

 from the third stage which it had left off before it 

 could complete its hammock." The rhythm of the 

 caterpillar's instinct was so mechanical ; the creature 

 was in such abject slavery to its routine, that once the 

 rhythm was broken it could only recommence at the 

 point where the break took place, even though it 

 might greatly benefit by commencing somewhere else. 



It is very similar in the case of the rhythm of a 

 spider's instinct. The spider in the snare of ten turns 

 is unable, after all the turns are destroyed, to commence 

 in any other place than at the eleventh turn ; the spider 

 in the snare without any temporary spiral continues to 

 struggle on with its work, but is unable to reconstruct 



