482 HABITATIONS OF INSECTS. 



of clay composing these walls, and though connected 

 by no glutinous material, they appear when finished 

 one single layer well united, consolidated, and smooth- 

 ed. Having traced the plan of their structure, by- 

 placing here and there the foundations of the pillars 

 and partition-walls, they add successively new por- 

 tions; and when the walls of a gallery or apartment 

 which are half a line thick are elevated about half an 

 inch in height, they join them by springing a flattish 

 arch or roof from one side to the other. Nothing can 

 be a more interesting spectacle than one of these cities 

 while building. In one place vertical walls form the 

 outline, Avhicli communicate with different corridors 

 by openings made in the masonry ; in another we see 

 a true saloon whose vaults are supported by numerous 

 pillars ; and further on are the cross ways or squares 

 where several streets meet, and whose roofs, though 

 often more than two inches across, the ants are under 

 no difficulty in constructing, beginning the sides of the 

 arch in the angle formed by two walls, and extending 

 them by successive layers of clay till they meet : while 

 crowds of masons arrive from all parts with their par- 

 ticle of mortar, and work with a regularity, harmony, 

 and activity, which can never enough be admired. So 

 assiduous are they in their operations, that they will 

 complete a story with all its saloons, vaulted roofs, 

 partitions and galleries, in seven or eight hours. If 

 they begin a story, and for want of moisture are un- 

 able to finish itj they pull down again all the crumbling 

 apartments that are not covered in% 



Another species of ants (F.fusca, L.) are ifilso ma- 



" Huber, Recherches, &c. 30-40. 



