190 INSECT TRANSFORMATIONS. 



nettle, and blister the skin when touched; which is 

 also partly exemplified in that of our own gipsey moth 

 (Hypogymna dispar), the slender hairs of which 

 irritate and inflame the skin. The spines, in some of 

 the caterpillars alluded to, are like smooth thorns or 

 prickles; but on others, they are beset, or feathered 

 with shorter spines. 



It is probably for some purpose of defence or con- 

 cealment that the larvae of several insects form a sin- 

 gular covering for themselves of their own excrements, 

 which they pile up for that purpose upon their backs. 

 This material, as Kirby has observed, is not always so 

 offensive as might be supposed, being in some in- 

 stances ( Cassida maculata et Lnalidium Leayanutn) 

 formed into fine branching filaments, like lichens or 

 dried fucus.* Others, however, which Reaumur 

 aptly terms Hottentots, do not appear quite so cleanly. 

 One of these, rather uncommon, was observed, 

 many years ago, by Vallisnieri, which he calls the 

 cantharidis of the lily (Crioceris merdigera, LEACH), 

 and may be found in May on Solomon's-seal, and 

 other liliaceous plants, which it devours and renders 

 unsightly. Under its singular canopy, it has no 

 resemblance to an insect, but looks like an oblong 

 ball of chewed grass stuck on the lily. The beetle 

 which is produced from the grub is of a fine brownish 

 scarlet, and elegantly sculptured with minute dots. 

 Another species, more abundant, similar in man- 

 ners, and less than half the size of the preceding 

 (C. cyanella, PANZER), is of a fine blue colour, with 

 similar dottings. The grub of the green tortoise- 

 beetle (Cassida equestris, FABR.), usually found on 

 burdocks, is furnished with a more ingenious me- 

 chanism for this purpose, consisting of a fork in its 

 tail, which it can depress or elevate, so as to carry its 

 strange canopy higher or lower, at pleasure. Like 



* Linu. Trans, iii, 10. 



