SPINNING CATERPILLARS. 329 



which unite to form a common tent of leaves (see 

 pages 172, 3). The most common instance of this is 

 in the caterpillars which feed on the nettle — the small 

 tortoise-shell (Vanessa urtices), and the peacock's eye 

 (F. 16). Colonies of these may be seen, after Mid- 

 summer, on almost every clump of nettles, inhabiting 

 a thin web of an irregular oval shape, from which 

 they issue out to feed on the leaves, always returning 

 When their appetite is satisfied, to assist their com- 

 panions in extending their premises. Other ex- 

 amples, still more conspicuous from being seen on 

 fruit-trees and in hedges, occur in the caterpillars of 

 the small ermine-moth ( Yponomeuta padella), and 

 of the lackey (Clisiocampa neustria), which in some 

 years are but too abundant, though in others they 

 are seldom met with. In the summer of 1826, 

 every hedge and fruit-tree around London swarmed 

 with colonies of the ermine, though it has not since 

 been plentiful ;* and in the same way, during the 

 summer of 1829, the lackeys were to be seen every- 

 where. We mention this irregularity of appearance 

 that our readers may not disappoint themselves by 

 looking for what is not always to be found. It is 

 probable, that, in 1830, the lackeys will be few, for, 

 notwithstanding the myriads of caterpillars last sum- 

 mer, we saw only a single moth of this species, and 

 out of a number of chrysalides which a young friend 

 had in his nurse-boxes, not one moth was bred. 



The caterpillars of other moths, which are in some 

 years very common — such as the brown-tail (Por- 

 thesia aurijlua), and the golden-tail (P. Chry- 

 sorrh&a), are also social ; and, as the eggs are 

 hatched late in the summer, the brood passes the 

 winter in a very closely-woven nest of warm silk. 

 This is usually represented as composed of leaves 

 which have had their pulpy parts eaten as food 

 * See Insect Transformations, p. 206-7. 



