184 INSECT ARCHITECTURE. 



builds an arched wall so as to form a chamber con- 

 siderably larger than is usual with other architect 

 caterpillars. It selects grains of mortar, brick, or 

 lichen, fixing them, by means of silk, firmly into the 

 structure. As some of these vaulted walls were 

 from an inch to an inch and a half long, and about a 

 third of an inch wide and deep, it may be well 

 imagined that it would require no little industry and 

 labour to complete the work. Yet it does not de- 

 mand more than a few hours for the insect to raise it 

 from the foundation. Like all other insect architects, 

 this caterpillar uses its own body for a measuring 

 rule, and partly for a mould, or rather a block or 

 centre to shape the walls by, curving itself round and 

 round concentrically with the arch which it is building. 

 We afterwards found one of these caterpillars, 

 which had dug a cell in one of the softest of the 

 bricks, covering itself on the outside with an arched 

 wall of brick-dust, cemented with silk. As this brick 

 was of a bright red colour, we were thereby able to 

 ascertain that there was not a particle of lichen em- 

 ployed in the structure. 



The neatness mentioned by Reaumur, as remark- 

 able in his moss-building caterpillars, is equally ob- 

 servable in that which we have just described ; for, on 

 looking at the surface of the wall, it would be impos- 

 sible for a person unacquainted with these structures 

 to detect where they were placed, as they are usually, 

 on theoutside, level with the adjoining brick-work, and 

 (t is only when they are opened by the entomologist, 

 that the little architect is perceived lying snug in his 

 chamber. If a portion of the wall be thus broken 

 down, the caterpillar loses no time in repairing the 

 breach, by piecing in bits of mortar and fragments of 

 lichen, till we can scarcely distinguish the new por- 

 tion from the old. 



