GREEN-OAK MOTH. 139 



having sufficient inductive reason to trace the silken 

 thread and so find the caterpillar, goes off to try its 

 fortune elsewhere. The danger being over, the 

 caterpillar ascends its silken ladder, and quietly 

 regains possession, of its home. 



Myriads of these rolled leaves may be found on 

 the oak trees, and the caterpillars may be driven out 

 in numbers by a sharp jar given to a branch. It is 

 quite amusing to see the simultaneous descent of 

 some hundred caterpillars, each swaying in the 

 breeze at the end of the line, and occasionally drop- 

 ping another foot or so, as if dissatisfied with its 

 position. 



Each caterpillar consumes about three or four 

 leaves in the whole of its existence, and literally eats 

 itself out of house and home. But when it has eaten 

 one house, it only has to walk a few steps to find the 

 materials of another, and in a very short time it is 

 newly lodged and boarded. 



The perfect insect is called the " Green Oak Moth ". 

 The colour of its two upper wings is a bright apple 

 green ; and as the creature generally sits with its 

 wings closed over its back, it harmonises so perfectly 

 with the green oak leaves, that even an accustomed 

 eye fails to perceive it. So numerous are these little 

 moths, that their progeny would shortly devastate a 

 forest, were they not subject to the attacks of another 

 insect. This insect is a little fly of a shape some- 

 thing resembling that of a large gnat ; and which 



