MINING CATERPILLARS. 



205 



leaf, produced by the caterpillar of Eay's golden-silver 

 spot {Argyromiges Rayella? Curtis), of which we have 

 just gathered above a dozen specimens from one rose-tree. 

 (J-E.) 



It may be remarked that the winding line is black, 

 closely resembling the tortuous course of a river on a 

 map, — beginning like a small brook, and gradually in- 

 creasing in breadth as it proceeds. This representation 

 of a river exhibits, besides, a narrow, white valley on each 

 side of it, increasing as it ^oes, till it terminates in a broad 

 delta. The valley is the portion of the inner leaf from 



Leaf of the Monthly Rose {Bose Indica}, mined by Caterpillars of Argyroniiges ? 



which the caterpillar has eaten the pulp (parenchyma), 

 while the river itself has been formed by the liquid ejecta- 

 menta of the insect, the watery part becoming evaporated. 

 In other species of miners, however, the dung is hard and 

 diy, and consequently these only exhibit the valley without 

 the river (see p. 207). 



On looking at the back of the leaf, where the winding 

 line begins, we uniformly find the shell of the very minute 

 egg from which the caterpillar has been hatched, and 

 hence perceive that it digs into the leaf the moment it 

 escapes from the egg, without wandering a hair's-breadth 

 from the spot ; as if afraid lest the air should visit it too 



