130 A NATURALIST IN HIMALAYA 



has a centre. Yet the spider works mechanically on. 

 How blind is this instinct that impels the spider in 

 this course ! A single bridge would improve matters ; 

 it could not remedy them now, for the damage is too 

 great. But it is all the same to the spider. To 

 construct a bridge now is far beyond its mental power ; 

 it can only circle mechanically on. I was amazed to 

 think that a creature could be compelled by such a 

 blind unswerving instinct to circle round and round 

 the formless web, and driven by so unalterable a 

 mental stimulus to weave such a shapeless and 

 imperfect structure. 



I modified the experiment in different ways. I 

 divided the outer bridges in two adjoining segments, 

 but the spider crossed over by the second line of 

 bridges. I divided all the outer bridges in all the 

 segments, and the spider crossed by the second circle 

 of bridges. I have no doubt that if I had removed 

 the second circle, then the spider would have used the 

 third circle ; or if I had removed the third circle, then 

 it would have used the fourth circle ; but what it never 

 would have done was to construct a new bridge. 



But one experiment will include all. I found a 

 snare with twenty-one radii and a temporary spiral of 

 six turns. The spider had commenced the viscid 

 spiral and five turns were complete. I removed the 

 whole of the temporary spiral in every segment. That 

 is, I divided 126 possible bridges, so that the spider 

 had now no bridge left in any segment. It must either 

 build new bridges or continue right into the centre at 

 every passage from radius to radius. It must either 

 go back on its work or face tremendous obstacles. 

 What will the spider do now? Its difficulties are 



