238 INSECT ARCHITECTURE. 



that, in warm climates, worms an inch long are found 

 in leaves, and adds, with great simplicity, " on these 

 many fine experiments might have been made, if 

 the inhabitants had not laboured under the cursed 

 thirst of gold."* 



The vine-leaf miner, when about to construct its 

 cocoon, cuts, from the termination of its gallery, two 

 pieces of the membrane of the leaf, deprived of their 

 pulp, in a similar manner to the tent-makers de- 

 scribed above, uniting them and lining them with 

 silk. This she carries to some distance before she 

 lays herself up to undergo her change. Her mode 

 of walking under her burthen is peculiar, for, not 

 contented with the security of a single thread of silk, 

 she forms, as Bonnet says, " little mountains (mon- 

 ticules) of silk, from distance to distance, and seizing 

 one of these with her teeth, drags herself forward, and 

 makes it a scaffolding from which she can build 

 another."t Some of the miners, however, do not 

 leave their galleries, but undergo their transforma- 

 tions there, taking the precaution to mine a cell, not 

 in the upper, but in the under surface ; others only 

 shift to another portion of the leaf. 



Social Leaf-Miners. 



The preceding descriptions apply to caterpillars 

 who construct their mines in solitude, there being 

 seldom more than one on a leaf or leaflet, unless 

 when two mother- flies happen to lay their eggs on the 

 same leaf; but there are others, such as the miners 

 of the leaves of the henbane (Hyoscyamus niger), 

 which excavate a common area in concert — from four 

 to eight forming a colony. These are very like flesh- 

 maggots, being larger than the common miners ; the 



* Swammerd. Book of Nature, vol. ii. p. 84. 

 t Contempl. de la Nature, part xii. p. 197. 



