134 THE WONDERS OF INSTINCT 



tends to his duties as a leader and is continually turning 

 his head to this side and that, investigating, seeking, 

 groping, making his choice. And things happen as he 

 decides: the band follows him faithfully. Remember 

 also that, even on a road which has already been traveled 

 and beribboned, the guiding caterpillar continues to ex- 

 plore. 



There is reason to believe that the Processionaries 

 who have lost their way on the ledge will find a chance 

 of safety here. Let us watch them. On recovering 

 from their torpor, the two groups line up by degrees into 

 two distinct files. There are therefore two leaders, free 

 to go where they please, independent of each other. 

 Will they succeed in leaving the enchanted circle? At 

 the sight of their large black heads swaying anxiously 

 from side to side, I am inclined to think so for a moment. 

 But. I am soon undeceived. As the ranks fill out, the 

 two sections of the chain meet and the circle is reconsti- 

 tuted. The momentary leaders once more become simple 

 subordinates ; and again the caterpillars march round and 

 round all day. 



For the second time in succession, the night, which 

 is very calm and magnificently starry, brings a hard frost. 

 In the morning the Processionaries on the tub, the only 

 ones who have camped unsheltered, are gathered into a 

 heap which largely overflows both sides of the fatal 

 ribbon. I am present at the awakening of the numbed 

 ones. The first to take the road is, as luck will have it, 

 outside the track. Hesitatingly he ventures into un- 



