VOL. LXXI.] PHILOSOPHICAL TRANSACTIONS. 69 



of those hills. Those however which are built by the smaller species of those 

 insects, are very numerous, and some of them exceedingly well worth our 

 attention; one sort in particular, which from their form Mr. S. has named turret 

 nests. These are a great deal less than the foregoing, and indeed much less in 

 proportion to the size of the buildings; but their external form is more curious, 

 and, their solidity considered, they are prodigious buildings for so small an 

 animal.* 



These buildings are upright cylinders composed of a well-tempered black earth 

 or clay, about -f- of a yard high, and covered with a roof of the same material in 

 the shape of a cone, whose base extends over and hangs down 3 or 4 inches 

 wider than the perpendicular sides of the cylinder; so that most of them 

 resemble in shape the body of a round windmill; but some of the roofs have so 

 little elevation in the middle, that they are pretty much in the shape of a full- 

 grown mushroom. 



After one of these turrets is finished, it is not altered or enlarged ; but when 

 no longer capable of containing the community, the foundation of another is 

 laid within a few inches of it. Sometimes, though but rarely, the 2d is begun 

 before the first is finished, and a 3d before they have completed the 2d: thus 

 they will run up 5 or 6 of these turrets at the foot of a tree in the thick woods, 

 and make a most singular group of buildings. The turrets are so strongly built, 

 that in case of violence they will much sooner overset from the foundation, and 

 tear up the gravel and solid earth, than break in the middle; and in that case the 

 insects will frequently begin another turret and build it, as it were, through that 

 which is fallen ; for they will connect the cylinder below with the ground, and 

 run up a new turret from its uppet side, so that it will seem to rest on the hori- 

 zontal cylinder only. 



Mr. S. did not observe any thing else about these nests that was remarkable, 

 except the quantity of the black brown clay, which is as dark coloured as rich 

 vegetable mould, but burns to an exceeding fine and clear red brick. Within, 

 the whole building is pretty equally divided into innumerable cells of irregular 

 shapes; sometimes they are quadrangular or cubical, and sometimes pentagonal; 

 but often the angles are so ill defined, that each half of a cell will be shaped like 

 the inside of that shell which is called the sea-ear. Each shell has two or more 

 entrances, and as there are no pipes or galleries, no variety of apartments, no 

 well-turned arches, wooden nurseries, &c. &c. they do not by any means excite 

 our admiration so much as the hill nests, which are indeed collections of won- 

 ders. There are two sizes of these turret nests, built by two different species of 



* If their height be estimated and computed by the size of the builders, and compared with ours 

 on the like scale ; each of them is 4 or 5 times the height of the monument, and a great many times 

 its solid contents. — Orig. 



