HABITATIONS OF INSECTS. 307 



far from Injuring, consolidates and strengthens their architecture. Different 

 laborers convey small masses of this ductile material between their man- 

 dibles, and with the same instrument they spread and mould it to their 

 will, the antennae accompanying every movement. They render all firm 

 by pressing the surface lightly with their fore feet ; and however numerous 

 the masses of clay composing these walls, and though connected by no 

 glutinous material, they appear when finished one single layer well united 

 consolidated, and smoothed. Having traced the plan of their structure, 

 by placing here and there the foundations of the pillars and partition- 

 walls, they add successively new portions ; and when the walls of a gal- 

 lery 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, which 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 roots, 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 particle 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 unable to finish it, thgy 

 pull down again all the crumbling apartments that are not covered in.^ 



Another species of ants (F. fusca) are also masons. When they wish 

 to heighten their habitations, they begin by covering the top with a thick 

 layer of clay, which they transport from the interior. In this layer they 

 trace out the plan of the new story, first hollowing out little cavities of 

 almost equal depth at different distances from each other, and of a 

 size adapted to their purposes. The elevations of earth left between them 

 serve for bases to the interior walls, which, when they have removed all 

 the loose earth from the floors of the apartments, and reduced the founda- 

 tions to a due thickness, they heighten, and lastly cover all in. M. 

 Huber saw a single working ant make and cover in a gallery which was 

 two or three inches long, and of which the interior was rendered perfectly 

 concave, without assistance.^ 



The societies of F. fuliginosa make their habitations in the trunks of 

 old oaks or willow trees, gnawing the wood into numberless stories more 

 or less horizontal, the ceilings and floors of which are about five or six lines 

 asunder, black, and as thin as card, sometimes supported by vertical parti- 

 tions, forming an infinity of apartments which communicate by small 

 apertures ; at others by small light cylindrical pillars furnished with a base 

 and capital which are arranged in colonnades, leaving a communication 

 perfectly free throughout the whole extent of the story .^ 



Two other tribes of carpenter ants (F. cBthiops and F. Jlava) use saw- 

 dust in forming their buildings. The former applies this material only to 



1 Huber, Recherches, &c. 30—40. » Ibid. 45. » Ibid. 53. 



