224< STATES OF INSECTS. 



resemble gauze or lace a . Of the first description is one 

 in my cabinet before alluded to, shaped somewhat like 

 an air-balloon; the meshes are large and perfectly square. 

 The pupa hangs in the centre, fixed by some few slight 

 threads which diverge from it to all parts of the cocoon — 

 so that it looks as if it was suspended in the air, like 

 Mahomet's coffin, without support. Of the second de- 

 scription is a black one with very fine and nearly circular 

 meshes : the threads that form these are thick, and seem 

 to be agglutinated. In our own country, the cocoons of 

 some beetles, as ofcHypera Arator, Galeruca Tanaceti,and 

 of some little Tinece, also resemble gauze. Many of the 

 larvae, however, which spin these cocoons, whose thin- 

 ness is probably attributable to the smallness of their 

 stock of silk, seem anxious for a more complete conceal- 

 ment ; and therefore commonly either hide them between 

 leaves tied together, in some with a certain regularity, 

 in others without art b ; or thicken their texture, and 

 render it opaque, by the addition of grains of earth c , 

 or of other materials with which their bodies sup- 

 ply them. These are principally of two kinds. The 

 larvae of Lasiocampa Neustria, Arctia Salic is, &c. after 

 spinning their cocoons, cast from their anus three or four 

 masses of a soft and paste-like matter, which they apply 

 with their head all round the inside of the cavity ; and 

 which, drying in a short time, becomes a powder that 

 effectually renders it opake. This is not, as might be 

 conjectured, an excrement, but a true secretion, evidently 



a Plate XVII. Fig. 8. 



b The thick cocoons of Atiacus Paphia, Polyphemus, &c. are also 

 thus fastened between leaves. 

 c Merian Europ. ii. /. ix. 



