THE INSTINCT OF SPIDERS 141 



in patience at the centre. It set about to demolish the 

 snare. It moved out along each radius eating up the 

 fabric in its progress. Methodically it worked until 

 it had devoured all. When the snare had been com- 

 pletely destroyed with the exception of the foundation- 

 lines the spider then took up the work of construction. 

 It began to lay a new snare in the foundations of 

 its alien predecessor. 



The Arane^t,s, which I removed from the snare 

 completed up to two turns, I placed in that of the 

 Tetragnatha completed up to seventeen turns. Now 

 this was an advantage to the Araneus. The new snare 

 was more complete. Much of the work had been done 

 by the Tetragnatha that it had replaced. If the Ara- 

 neus just continued the work and brought the snare to a 

 completion, it would gain much by the expenditure of 

 less silk. But I felt sure that the spider could not do 

 this. It first explored the snare. Then, unsatisfied 

 with the exchange, it behaved like the Tetragnatha in 

 the previous experiment ; it ate up the whole snare. 

 All the new radii, all the complete bridges, the 

 seventeen turns of the viscid spiral, just newly spun, 

 were systematically destroyed. In this instance the 

 spider was in a position to gain by the transfer. But 

 it was unable to reap any advantage from the half- 

 completed work. It must commence again from the 

 very beginning. 



Similarly have I transferred Araneus nauticus while 

 engaged on construction, to another snare of its own 

 species. I have sometimes seen it rest satisfied with 

 the transfer and resume the work, but often it de- 

 stroyed the snare. I am unable to understand why a 

 spider sometimes accepts and sometimes rejects a new 



