364 Insect Architecture. 



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

 named by Reaumur the Processionary (Cnethocamga pro- 

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

 when newly hatched, into one or more parties of several 

 hundred individuals, which afterwards unite in constructing a 

 common nest nearly two feet long, and from four to six 

 inches in diameter. As it is not divided like that of the 

 brown-tails into chambers, but consists of one large hall, it is 

 not necessary that there should be more openings than one ; 



Nest and order of inarching of the Processionary Caterpillars of the oak (Onethocampa 

 processioned). 



and accordingly, when an individual goes out and carpets a 

 path, the whole colony instinctively follow in the sa*me track, 

 though from the immense population they are often com- 

 pelled to march in parallel files from two to six deep. The 

 procession is always headed by a single caterpillar; some- 

 times the leader is immediately followed by one or two in 

 single file, and sometimes by two abreast, as represented in 

 the cut. A similar procedure is followed by a species of 

 social caterpillars which feed on the pine in Savoy and 

 Languedoc ; and though their nests are not half the size of 



