HABITATIONS OF INSECTS. 271 



consolidates and strengthens their architecture. Different labourers con- 

 vey small masses of this ductile material between their mandibles, 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 sur- 

 face 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 gallery or apartment, 

 which are half a line thick, are elevated about half an inch in height, 

 they join them by springing a flatfish 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 com- 

 municate 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 particle of mortar, and work with a regularity, harmony, and activity, 

 which can never enough be admired. So assiduous are they in their opera- 

 tions, 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, they pull down again all the 

 crumbling apartments that are not covered in. 1 



Another species of ants (M.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 for 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 foundations 

 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. 2 



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 aper- 

 tures ; 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. 3 



Two other tribes of carpenter ants (F. ccthiops and 'F.flava) use saw- 

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



1 Huber, Recherches, &c. 3040. 2 Ibid. 45. 



3 Ibid. 53. 



