40 ON ENTOMOLOGY. 



corridors by apertures formed in the masonry, on another a regularly 

 formed hall was constructed, the vaulted ceiling of which was sustained 

 by numerous pillars ; further off again might be recognized the rudi- 

 ments of one of those cross-roads of which I have before spoken, and 

 in which several avenues terminate. These parts of the Ant-hill were 

 the most spacious ; the Ants, however, did not appear embarrassed in 

 constructing the ceiling to cover them in, although they were often more 

 than two inches in breadth. In the upper part of the angles formed by 

 the different walls, they laid the first foundations of this ceiling, and 

 from the top of each pillar, as from so many centres, a layer of earth, 

 horizontal and slightly convex, was carried forward to meet the several 

 portions coming from different points of the large public thoroughfare. 

 I sometimes, however, laboured under an apprehension that the building- 

 could not possibly resist its own weight, and that such extensive ceil- 

 ings, sustained only by a few pillars, would fall into ruins, from the 

 rain which continually dropped upon them ; but I was quickly con- 

 vinced of their stability, from observing that the earth brought by these 

 insects adhered at all points on the slightest contact, and that the rain so 

 far from lessening the cohesion of its particles, appeared even to in- 

 crease it. Thus, instead of injuring the building, it even contributed to 

 render it still more secure. These particles of moistened earth, which 

 are only held together by juxta position, require a fall of rain to cement 

 them more closely, and thus varnish over, as it were, those places where 

 the walls and galleries remain uncovered. All inequalities in the ma- 

 sonry then disappear. The upper part of these stories, formed of seve- 

 ral pieces brought together, presents but one single layer of compact 

 earth. They require for their consolidation nothing but the heat of the 

 sun. It sometimes, however, happens, that a violent rain will destroy 

 the apartments, especially should they be but slightly arched, but under 

 these circumstances the Ants re-construct them with wonderful patience. 

 These different labours were carried on at the same time, and were so 

 closely followed up in the different quarters, that the Ant-hill received 

 an additional story in the course of seven or eight hours. All the 

 vaulted ceilings being formed upon a regular plan, and at equal distances, 

 from one wall to the other, constituted, when finished, but one single 

 roof. Scarcely had the Ants finished one story than they began to con- 

 struct another, but they had not time to finish it, the rain ceasing before 

 the ceiling was fully completed. They still, however, continued, their 

 work for a few hours, taking advantage of the humidity of the earth, but 

 a keen north wind soon sprung up and hastily dried the collected frag- 

 ments, which no longer possessing the same adherence fell into powder. 

 The Ants finding their efforts ineffectual, were at length discouraged ; 

 but what was my astonishment when I saw them destroy all the apart- 

 ments that were yet uncovered scattering here arid there over the last 

 story, the materials of which they had been composed. These facts in- 

 contestibly prove that they enploy neither gum nor any kind of cement 



