LEPIDOPTEEA. 



159 



causing the greater part of them, to curve at their upper extremity, 

 in such a manner as to form a sort of cradle. 



It remains for us now to speak of the caterpillars that make 

 their cocoons of silk, together with other materials. Reaumur saw 



Fig. 118. Small Caterpillar of the Pimpernel. 



Fig. 119. Cocoon of the same. 



the Pimpernel caterpillar arranging and sticking together the 

 leaves of that plant, and spinning underneath them a thin cocoon 

 of white silk (Fig. 119). 



Some caterpillars make their cocoons on the surface of the 

 earth, and even with earth. These cocoons are spherical or 

 oblong. Their exterior is more or less well shaped, but their 

 interior is always smooth, polished, shining like moistened earth, 

 worked up together into a kind of paste, and carefully smoothed 

 out. This cocoon is besides lined with a covering of silk of 

 variable thickness. The shell is not made of earth alone ; threads 

 of silk may be seen in it, crossing each other, and binding 

 together the particles of earth. 



These subterranean workers do not allow their proceedings to 

 be easily observed. Reaumur was fortunate enough to be able to 

 discover the artifice they employ in the construction of their shells 

 or cocoons. The Cucullia verbasd (Fig. 120) makes itself a 

 thick and very compact cocoon of the form of an egg (Fig. 121). 

 Reaumur took one of these out of the ground before it was 

 fortified. He tore it partially open, and placed it in a glass 

 vase containing sand, but the poor insect was not long in repair- 

 ing the disorder caused by the rough hand of our naturalist. It 

 only took four hours to restore its cocoon to its former state. 



"It began," says Reaumur, "by coming almost entirely out, 



