HABITATIONS OF INSECTS. 457 



making any incision, prudently run (as a sempstress 

 would call it) loosely together in distant points the two 

 membranes on that side. Then putting out their heads 

 they cut the intermediate portions, carefully avoiding the 

 larger nerves of the leaf; afterwards they sew up the de- 

 tached sides more closely, and only intersect the nerves 

 when their labour is completed a . The habitation made 

 by a moth, which lives upon a species of Astragalus, is 

 in like manner formed of the epidermis of the leaves, but 

 in this several corrugated pieces project over each other, 

 so as to resemble the furbelows once in fashion 5 . 

 " Other larvae construct their habitations wholly of silk. 

 Of this description is that of a moth, whose abode, ex- 

 cept as to the materials which compose it, is formed on 

 the same general plan as that just described, and the 

 larva in like manner feeds only on the parenchyma of 

 the leaf. In the beginning of spring, if you examine 

 the leaves of your pear-trees, you will scarcely fail to 

 meet with some beset on the under surface with several 

 perpendicular downy russet-coloured projections, about 

 a quarter of an inch high, and not much thicker than a 

 pin, of a cylindrical shape, with a protuberance at the 

 base, and altogether resembling at first sight so many 

 spines growing out of the leaf. You would never sus- 

 pect that these could be the habitations of insects ; yet 

 that they are is certain. Detach one of them, and give 

 it a gentle squeeze, and you will see emerge from the 

 lower end a minute caterpillar with a yellowish body 

 and black head. Examine the place from which you 

 have removed it, and you will perceive a round excava- 

 tion in the cuticle and parenchyma of the leaf, the size 

 a Reaum. iii. 100-120. b Ibid. 146. 



