188 LARGE CABBAGE BUTTERFLY. 



hardens in the air, so that they have no difficulty in 

 making it stick to the glass. 



Many caterpillars that feed upon trees, particularly 

 the Geometers, have often occasion to descend from 

 branch to branch, and sometimes to the ground 

 especially previous to their assuming the pupa 

 condition. Had they to descend by the trunk, 

 supposing them able to traverse with ease its rugged 

 bark, what a circuitous route must they take before 

 they accomplish their purpose! Providence, ever 

 watchful over the welfare of the most insignificant of 

 its creatures, has gifted them with the means of 

 attaining these ends, without all this labour and loss 

 of time. From their own internal stores, they can 

 let down a rope, and prolong it indefinitely, which 

 will enable them to travel where they please. Shake 

 the branches of an oak, or other tree, in summer, 

 and its inhabitants of this description, whether they 

 are reposing, moving, or feeding, will immediately 

 cast themselves from the leaves on which they 

 are stationed ; and, however sudden the attack, 

 they are nevertheless provided for it, and will all 

 descend by means of the silken cord alluded to, 

 and hang suspended in the air. Their name, 

 Geometer, was given them because they seem to 

 measure the surface they pass over, as they walk, 

 with a chain. If one is placed on the hand, it will 

 be felt to draw a thread as it moves. When they 

 move, their head is extended as far as they can reach 

 with it ; then, fastening their thread there, and 

 bringing up the rest of their body, they take another 



