OF SOCIABLE CATERPILLARS. 95 



the colony leaves its quarters, and sets out on its 

 excursive rambles. They are led by a chief, who 

 regulates all their movements ; three, or sometimes 

 four, of his immediate followers, move in the same 

 line, the head of each touching the tail of his 

 nrecursor. Their movement is in a sort of pyramidal 

 form ; for after these Indian file, there comes a 

 series in pairs, after them a number in threes, fours, 

 and increasing systematically, till the column is con- 

 cluded by rows of from fifteen to twenty. This little 

 army (if I may be allowed the expression) proceeds 

 with a steady movement, each animal following in 

 direct line that which precedes it. If their leader 

 makes a turn at any particular point, the whole of his 

 followers arrive at the same spot before they make a 

 wheel. They may be guided in this movement 

 by a particular odour left by the leader on the line 

 of his march. This is not, however, their invariable 

 order of proceeding. 



The leader has nothing different in his appearance 

 from the others, and is in all probability the one 

 nearest the tent when they set out ; at least, such is 

 Reaumur's opinion. When he first issues from his 

 retreat, he moves forward about two feet, less or 

 more, according to the numbers of his followers, who 

 now appear from out their cell, and rank them- 

 selves in the manner before described, and when 

 this is completed, they move off with the regularity 

 of an army marching to a band of music. 



The larvae of the Processionary Bombyx are some- 

 times, although rarely, seen in the open air at 



