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INSECT ARCHITECTURE. 



In all the nests of social caterpillars, care is taken to 

 leave apertures for passing out and in. It is remarkable, 

 also, that however far they may ramble from their nest, 

 they never fail to find their way back when a shower of 

 rain or nightfall renders shelter necessary. It requires no 

 great shrewdness to discover how they effect this : for by 

 looking closely at their track it will be found that it is 

 carpeted with silk — no individual moving an inch without 

 constructing such a pathway, both for the use of his com- 

 panions and to facilitate his own return. All these social 

 caterpillars, therefore, move more or less in processional 

 order, each following the road which the first chance travel- 

 ler has marked out with his strip of silk carpeting. 



There are some species, however, which are more remark- 

 able than others in the regularity of their processional 

 marchings, particularly two which are found in the south 

 of Europe, but are not indigenous in Britain. The one 

 named by Eeaumur the processionary (Cnethocampa jjro- 



Nest and order uf marching of tlie Processionary Caterpillars of the oak {Cnethocampa 

 j/)-ocessionea'). 



cessionea, Stephens) feeds upon the oak ; a brood dividing, 

 when newly hatched, into one or more parties of several 



