RAVAGES OF CATERPILLARS. 211 



cages; but, contrary to the experiment just quoted, 

 all of these were hatched during the same autumn*. 

 The ditference of temperature and moisture in par- 

 ticular seasons may produce this diversity. 



An alarm, similar to those vve have recorded, was 

 produced in France in 1735 by the green striped 

 caterpillars of a moth very common in Britain, called 

 by collectors, from a mark on its upper wings, the Y, 

 or more properly the y moth (Plusia Gamma, Ochs.) 

 Though ranked in some classifications amongst the 

 nocturnal moths, it flies chiefly by day, and may be 

 seen in Battersea-fields, or other moist meadows, flit- 

 ting from herb to herb and flower to flower, in short 

 and low flights; for it seldom soars higher than the 

 tallest grass-stem, or the crimson flower-heads of the 

 knap-weed, upon whose honey it sometimes regales, 

 remaining on the wing all the while it is sipping it. 

 During the cold rainy summer of 1829 it was almost 

 the only moth which appeared plentiful f. At least 

 two broods seem to be jjroduced during the season ; 

 which may account for its being found from May till 

 the setting-in of the winter frosts. 



Notwithstanding it being so plentiful, however, 

 we have hot heard of its having ever been so destruc- 

 tive here as in France, where, as usual, the most 

 improbable causes were assigned for its increase. 

 '* In some places," says Reaumur, "they assured 

 me they had seen an old soldier throw the spell ; and 

 in other places an ugly and mischievous old woman 

 had wrought all the evil J." These supposed super- 

 natural agents, however, must have been either very 

 numerous or very active to fill, not only the gardens 

 but every field, with legions of those caterpillars, which 

 devoured almost every green thing, and left only, 

 the stalks as monuments of their devastation. The 

 alarm proceeded farther, for it began to be whispered 

 * J. R. i J. R. + Reaumur, ii. 336. 



