302 IMPERFECT SOCIETIES OF INSECTS. 



inside of the pomegranate, on the seeds and pulp of which it feeds. The 

 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 larvae. 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 suf- 

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

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

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

 phosis, the butterflies while their wings are still unexpanded creeping out 

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

 pose 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 instru- 

 ments. 1 



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 favoured admirers, Bonnet, to see several hundreds of the 

 Iarva3 of Clisiocampa nenstria marching after each other, some in straight 

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

 colour, a moving cord of gold stretched upon a silken riband of the purest 

 white; this riband 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 mul- 

 titude 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. 2 



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

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

 (Cnethocampa 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 600 individuals. When young, they have no fixed habita- 

 tion, 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 

 harmonise with the trivial name of the animal, the monks their ccenobium. 

 At their head is a chief, by whose movements their procession is regulated. 

 When he stops, all stop, and proceed when he proceeds ; three or four of 



* West wood in Trans. Ent. Soc. Lond. ii. 1. tab. 1. The Mexican butterfty 

 (Eucheira socialis Westw.), previously noticed, is also (as its name implies) social in 

 its larva state. 



2 Bonnet, ii. 57. 



