114 THE NATURALIST IN AUSTRALIA. 
however, considers Smeathman to have been mistaken in attributing to this form 
wood-destroying properties which he correlates with a smaller species more nearly 
resembling, if not identical with, Hutermes arboreum. 
The second form of White Ant hills or termitaria described by Smeathman is 
referred to by him as being the joint work of two species of Termites, upon which 
Dr. Solander had conferred the respective titles of. Termes mordax and T. atrox, In 
each instance the nest consists of perpendicular cylindrical columns about three quarters 
of a yard high, consisting of very firmly consolidated black brown earth or clay and 
surmounted by an overlapping conical roof of the same material, which imparts to 
them an aspect comparable to that of gigantic mushrooms. The substance of these 
termitaria is described as being of such rigid consistence that the whole structure can 
be more easily uprooted from its earth foundation than fractured across the centre 
of the cylindrical column. It was further observed of examples that had become thus 
accidentally overturned, that the inhabitants commenced the construction of a new 
column, vertically and at right angles from the prostrate one. The internal structure of 
these so-called turret-nests are described by Smeathman as presenting none of the system- 
atic complexity possessed by the hillocks of Termes bellicosus, consisting entirely of 
innumerable. cells of irregular shape, each of which possessed two or more entrances 
by which it communicated with its neighbours. After one of these turret-nests is 
finished, it is not further altered or enlarged, but another column is constructed 
within a few inches of the first. A group of half-a-dozen or more of these mushroom- 
like termitaria is described as being often seen at the foot of the trees in the thick 
woods. 
The fourth variety of West African nest-constructing Termites, figured and 
described by Smeathman, is distinguished by the title of Termes arboreum. As its 
name implies, it builds its nest on the arms or stems of trees, sometimes at the 
considerable height of seventy or eighty feet from the ground. This nest or termitarium 
is usually spherical or oval in shape, and may be as large as a sugar cask. The 
substance out of which it’ is composed differs from that of the hillock and turret- 
shaped varieties. It consists, in place of clay, of minute particles of wood, combined 
with the gums and juices of trees, and built up into innumerable little cells of 
irregular shape and size. These nests are described as being so compact that there 
is no detaching them, except by cutting them in pieces or sawing off the branch upon 
which they are built, and to which, indeed, they are so firmly united that they will even 
resist the force of the tornadoes to which they are not unfrequently exposed, so long 
