HABITATIONS OF INSECTS. 4 71 



commodalion — I shall select for description only two, 

 both the work of spiders, and alluded to in a former let- 

 ter, which indeed, with the exception of the inartificial 

 retreats made by the Achetce, Cicindelce, and perhaps a 

 few others, are the only ones properly belonging to it. 



The habitation of one of these {My gale ccementaria, 

 Latr., Aranea Sauvagesii, Dorthes,) is subterraneous, 

 not a mere shallow cavity, but a tube or gallery upwards 

 of two feet in length and half an inch broad. This tun- 

 nel, 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 information to the spider of 

 what is passing above. You doubtless suppose that in 

 saying door I am speaking metaphorically. 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, incre- 

 dible 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 inferior surface is con- 

 vex and smooth, the superior flat and rough, and so like 

 the adjoining earth as not to be distinguishable from it, 



