468 HABITATIONS OF INSECTS. 



or gallery upwards of two feet in length and half an inch 

 broad. This tunnel, so vast compared with the size of 

 the insect, it digs by means of its strong jaws in a steep 

 bank of bare clay, so that the rain may readily run off 

 without penetrating to its dwelling. Its next operation 

 is to line the whole from top to bottom with a web of fine 

 silk, which serves the double purpose of preventing the 

 earth that composes the walls from falling in, and, by its 

 connexion with the door of the orifice, of giving informa- 

 tion to the spider of what is passing above. You doubt- 

 less suppose that in saying door I am speaking metapho- 

 rically. It could never enter into your conception that 

 any animal, much less an insect, could construct any 

 thing really deserving of that name any thing like our 

 doors, turning upon a hinge, and accurately fitted to the 

 frame of the opening which it is intended to close. Yet 

 such a door, incredible as it may seem, is actually framed 

 by this spider. It does not indeed, like us, compose it 

 of wood, but of several coats of dried earth fastened to 

 each other with silk. When finished, its outline is as 

 perfectly circular as if traced with compasses ; the in- 

 ferior surface is convex and smooth, the superior flat and 

 rough, and so like the adjoining earth as not to be distin- 

 guishable from it. This door the ingenious artist fixes 

 to the entrance of her gallery by a hinge of silk, which 

 plays with the greatest freedom, and allows it to be 

 opened and shut with ease; and as if acquainted with the 

 laws of gravity, she invariably fixes the hinge at the 

 highest side of the opening, so that the door when pushed 

 up shuts again by its own weight. She has not less sa- 

 gaciously left a little edge or groove just within the en- 

 trance, upon which the door closes, and to which it fits 



