CONSTITUTION AND DEVELOPMENT OF TERMITES. 291 
I have never found Termes in the orange, lemon, or vine; 
but, unlike Calotermes, it is very common in cactus. It 
continues to live and flourish in perfectly dead and dry wood, 
even when employed in the construction of roofs, doors, 
furniture, casks, &c. 
It is characteristic that whereas Calotermes confines itself 
to the original host plant, Termes successively attacks fresh 
plants or timber, and may thus pass from the furniture of a 
house to a tree, or the reverse, or from one piece of furniture 
to another. The following facts are related to this peculiarity : 
A few workers of Termes, which are probably explorers, 
are sometimes found to make a spontaneous appearance in the 
open air and in broad daylight. 
On other occasions Termites travel by availing themselves 
of natural cracks, e. g. in lava, or by hollowing out small dry 
rootlets underground, or in reeds by means of the tubular 
lumen. Frequently they have recourse to galleries, which are 
quite distinct from the burrows made in wood, because they 
are fabricated or built up, so to say, by the insects themselves. 
They are therefore not merely miners, but also builders. 
These galleries are of two kinds, tubular or D-shaped in section. 
Galleries are usually constructed in tubular form in the absence 
of any suitable base on which to build them; if such be present 
the gutter-shaped gallery (semicircular in section) is resorted 
to, but even in this case that part of the base which is enclosed 
between the walls of the tunnel is incompletely cemented over. 
Galleries of the latter kind are made by preference in the angle 
of junction of two walls (Pl. 17, fig. 40). 
Gutter-shaped galleries may reach the considerable length 
of eight or more metres. In the choir of the principal church 
of Pedara I have seen such a tunnel leading from the stalls to 
a crack in the wall adjoining the wooden ceiling, in which the 
crack disappeared. The insects travelled between the choir 
and the ceiling by means of the tunnel and then of the crack, 
which they made use of apparently without modification. In 
such cases it is sometimes difficult to distinguish the track of 
the insects right up to the point where the gallery leaves off. 
