234 



INSECT ARCHITECTURE. 



caterpillars, the track of whose progress appears on 

 the upper surface in winding Unes. Let us take one 

 of the most common of these for an example, — that 

 of the rose-leaf, produced by the caterpillar of Ray's 

 golden-silver spot [^rgij7^omiges Tiaijellal Curtis) 

 of which we have just gathered above a dozen speci- 

 mens from one rose tree.* 



Leaf of the Monthly-Rose (Rosa Indira) mined by Caterpillars 

 of Argyromigcsf 



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 increasing in breadth as it proceeds. This 

 representation of a river exhibits, besides, a narrow 

 white valley on each side of it, increasing as it goes, 

 till it terminates in a broad delta. The valley is the 

 portion of the inner leaf from which the caterpillar 

 has eaten the pulp {parenchyma), while the river 

 itself has been formed by the liquid ejactamenta of 

 the insect, the watery part becoming evaporated. In 

 other species of miners, however, the dung is hard 



* J. R. 



