234 INSECT ARCHITECTURE. 



caterpillars, the track of whose progress appears on 

 the upper surface in winding lines. 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 (Argyromiges Rayella? Curtis), 

 of which we have just gathered above a dozen speci- 

 mens from one rose-tree.* 



Leaf of the Monthly Rose (Rose Tndica). mined by Caterpillars 

 of Argyromigest 



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 nas been formed by the liquid ejectamenta of 

 the insect, the watery part becoming evaporated. In 

 other species of miners, however, the dung is hard 



