140 THE WONDERS OF INSTINCT 



deduct one-half of the time. This leaves eighty-four 

 hours' walking. The average pace is nine centimeters ^ 

 a minute. The aggregate distance covered, therefore, is 

 453 meters, a good deal more than a quarter of a mile, 

 which is a great walk for these little crawlers. The 

 circumference of the vase, the perimeter of the track, 

 is exactly i m. 35.^ Therefore the circle covered, al- 

 ways in the same direction and always without result, 

 was described three hundred and thirty-five times. 



These figures surprise me, though I am already fa- 

 miliar with the abysmal stupidity of insects as a class 

 whenever the least accident occurs. I feel inclined to 

 ask myself whether the Processionaries were not kept up 

 there so long by the difficulties and dangers of the de- 

 scent rather than by the lack of any gleam of intelligence 

 in their benighted minds. The facts, however, reply that 

 the descent is as easy as the ascent. 



The caterpillar has a very supple back, well adapted 

 for twisting round projections or slipping underneath. 

 He can walk with the same ease vertically or horizontally, 

 with his back down or up. Besides, he never moves for- 

 ward until he has fixed his thread to the ground. With 

 this support to his feet, he has no falls to fear, no mat- 

 ter what his position. 



I had a proof of this before my eyes during a whole 

 week. As I have already said, the track, instead of keep- 

 ing on one level, bends twice, dips at a certain point 

 under the ledge of the vase and reappears at the top a 



1 2l4 inches. — Translator's Note. 

 24 feet 5 inches. — Translator's Note. 



