86 INSECT TRANSFORMATtONS. 



is worthy of remark, that this is the precise form of 

 tlie arch-stones of a bridge. They are, in fact, built 

 tog-ether in the arched form. This, together with the 

 strong cement employed in uniting them, renders 

 it difficult to crush them, though considerable force 

 be used for that purpose ; and this even when they are 

 slipped off the branch, round which they are set like 

 pearls on a bracelet, which is the name given them 

 by the French peasantry. The cement, also, is so 

 hard, that when pressed it resists the nail, though it 

 may be pierced with the point of a sharp knife; and 

 not being soluble in water, " nor in any other liquid," 

 says Swammerdam, " which I have tried,'' the heaviest 

 rain dashes upon the eggs without injury. 



Eggs of thelackcy-motb, wound spirally round a twig of haw- 

 thorn ; natural size, and magnified. 



It may be a question with some, when they com- 

 pare these naked eggs of the lackey-moth, exposed on 

 a bare branch, with the warm downy covering of those 

 of the gypsey-moth, how the former are protected 

 from the colds of winter. This is a question which 

 previous researches cannot fully answer, but one cir- 

 cumstance is obvious — the lackey's eggs are many 

 degrees harder than those of the gypsey, which may 

 be easily crushed. Pro])ably also, this may be con- 

 nected with their electrical state ; and that has always 



