GEOLOGIC WORK OF ANTS——BRANNER. 325 
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big nests it is sometimes nearly or quite a foot thick. Inside of this 
hard, thick covering the materials are quite soft and brittle, and the 
partitions are sometimes almost as thin as paper, though thicker in 
the larger nests. Where the mound stands on the ground, the eavi- 
Fic. 6.—Mound of termites or white ants, State of Minas Geraes, Brazil. 
[From a photograph by R. Crandall, July, 1909.} 
ties of the upper portion connect through the perforated base with 
subterranean excavations. 
Parts of the nests are made of the excrement of the inhabitants. 
I have often broken the nests or the covered roads of these insects 
