THE BROWN ANT. 147 



others were scooping out shallow hollows in the claj floor, the lit- 

 tle ridges that were left standing being the foundation of the new 

 walls. On these were dabbed the earthen pellets, and adjusted by 

 means of the mandibles or by pressure of the fore feet, thus re- 

 ceiving compactness and uniformity. The most difficult part of 

 such a task is the formation of the ceiling, but the ants do not ap- 

 pear to be at all embarrassed by so formidable an undertaking, 

 but can lay ceilings of two inches in diameter with perfect certain- 

 ty. The method of constructing the ceiling is by moulding the 

 clay pellets into each angle of the chamber and also to the top of 

 the pillars. As fast as one row of pellets becomes dry, a second 

 is added ; and the insects perform this delicate duty with such ac- 

 curacy, that although so many centres are employed, the parts al- 

 ways coincide in the proper spots. The peculiar kneading and 

 biting to which the clay pellets are subjected makes them exceed- 

 ingly tenacious, so that they adhere strongly on the slightest con- 

 tact. 



"When once these walls are completed, they are of very great 

 strength, and are only the more consolidated by rain and heat. 

 Before their completion, however, they do not appear to endure 

 the extreme either of heat or moisture, and are taken to pieces 

 by the little architects if a drought should check the supply of 

 that moisture, without which the work can not be properly com- 

 pacted. 



Mr. Eennie, who followed up the observations of Huber, makes 

 the following remarks on the nest of the ant: — "On digging cau- 

 tiously into a natural ant-hill, established upon the edge of a gar- 

 den walk, we were enabjed to obtain a pretty complete view of 

 the interior structure. There were two stories, composed of large 

 chambers, irregularly oval, communicating with each other by 

 arched galleries, the walls of all which were as smooth as if they 

 had been passed over by a plasterer's trowel. The floors of the 

 chambers, we remarked, were by no means either horizontal or 

 level, but all more or less sloped, and exhibiting in each chamber 

 at least two slight depressions of an irregular shape. We left the 

 under story of this nest untouched, with the notion that the ant 

 might repair the upper galleries, of which we had made a vertical 

 section ; but instead of doing so, they migrated during the day to 

 a large crack, formed by the dryness of the weather, about a yard 

 from their old nest.'" 



This description is accompanied by a sketch of a portion of the 



