IMPERFECT SOCIETIES OF INSECTS. 337 



fruit being thus rendered weak and unable to support its own weight would 

 be liable to have its stalk broken and to fall to the ground with the first 

 wind and there rot, in which state it would most probably be destructive 

 to the inclosed larvoe. To obviate this evil, the caterpillars when full fed 

 have the remarkable instinct to gnaw a hole about a quarter of an inch in 

 diameter through the hard shell of the fruit while it still remains on the 

 tree, and issuing through this hole to spin in common (as it would seem) 

 a silken web attached both to the stalk and the base of the fruit, and 

 sufficiently strong to support the pomegranate from falling in the event of 

 the stalk being broken by the wind ; and having thus secured the stability 

 of their chamber, they retire again into it, and there undergo their meta- 

 morphosis, the butterflies while their wings are still unexpanded creeping 

 out of the hole above mentioned, which thus serves a second important 

 purpose in their economy, of allowing them a free passage in their perfect 

 state through the hard shell of the pomegranate, which, if this door in it 

 had not previously been provided by the caterpillar with its jaws, would 

 have proved a fatal prison to the butterfly which has no such instruments.^ 



The most remarkable insects, however, that arrange under this class of 

 imperfect associates, are those that observe a particular order of march. 

 Though they move without beat of drum, they maintain as much regularity 

 in their step as a file of soldiers. It is a most agreeable sight, says one 

 of Nature's most favored admirers. Bonnet, to see several hundreds of the 

 larvaj of Clisiocampa neustria marching after each other, some in straight 

 lines, others in curves of various inflection, resembling, from their fiery 

 color, a moving cord of gold stretched upon a silken ribband of the purest 

 white; this ribband is the carpeted causeway that leads to their leafy 

 pasture from their nest. Equally amusing is the progress of another moth, 

 the Pityocampa, before noticed ; they march together from their common 

 citadel, consisting of pine leaves united and inwoven with the silk which 

 they spin, in a single line: in following each other they describe a multi- 

 tude of graceful curves of varying figure, thus forming a series of living 

 wreaths, which change their shape every moment: — all move with a 

 uniform pace, no one pressing too forward or loitering behind ; when the 

 first stops, all stop, each defiling in exact military order." 



A still more singular and pleasing spectacle, when their regiments march 

 out to forage, is exhibited by the caterpillars of the Processionary moth 

 (Ciiethocampa processionea) . This moth, which is a native of France, 

 and has not yet been found in this country, inhabits the oak. Each 

 family consists of from 600 to 800 individuals. When young, they have 

 no fixed habitation, but encamp sometimes in one place and sometimes in 

 another, under the shelter of their web : but when they have attained two 

 thirds of their growth, they weave for themselves a common tent, before 

 described. About sunset the regiment leaves its quarters ; or, to make 

 the metaphor harmonize with the trivial name of the animal, the monks 

 their coenobium. At their bead is a chief, by whose movements their pro- 

 cession is regulated. When he stops, all stop, and proceed when he 

 proceeds ; three or four of his immediate followers succeed in the same 



' Westwood in Trans. Ent. Soc. Loud. ii. 1. tab. 1. The Mexican butterfly, {Eucheira 

 socinlts Westw ) previously noticed, is also (as its name implies) social in its larva state. 

 2 Bonnet, ii. 57. 



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