SnXNING CATERPILLARS. 291 



hundred individuals, which aftei^wards 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 ; and accordingly, when an individual goes out and 

 carpets a path, the whole colony instinctively follow in the 

 same track, though from the immense population they are 

 often compelled to march in parallel files from two to six 

 deep. The procession is always headed by a single cater- 

 pillar; sometimes the leader is immediately followed by 

 I 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 the preceding, they are more worthy of notice, 

 from the strong and excellent quality of their silk, which 

 Keaumur was of opinion might be advantageously manufac- 

 tured. Their nests consist of more chambers than one, but 

 are furnished with a main entrance, through which the 

 colonists conduct their foraging processions. 



