292 ^Insect Architecture. 



cautiously into a natural ant-hill, established upon the edge 

 of a garden-walk, we were enabled to obtain a pretty com- 

 plete view of the interior structure. There were two stories, 

 composed of large chambers, irregularly oval, communi- 

 cating with each other by arched galleries, the walls of all 

 which were as smooth and well-polished 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 ants 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. 

 (J. E.) 



We put a number of yellow ants (Formica flava), with 

 their eggs and cocoons, into a small glass frame, more than 

 half full of moist sand taken from their native hill, and 

 placed in a sloping position, in order to see whether they 

 would bring the nearly vertical, and therefore insecure, por- 

 tion to a level by masonry. We were delighted to perceive 

 that they immediately resolved upon performing the task 

 which had been assigned them, though they did not proceed 

 very methodically in their manner of building ; for instead 

 of beginning at the bottom and building upwards, many of 

 them went on to add to the top of the outer surface, which 

 increased rather than diminished the insecurity of the whole. 

 Withal, however, they seemed to know how far to go, for no 

 portion of the newly-built wall fell , and in two days they 



