BIOLOGY OF THE TERMITES OF THE EASTERN UNITED STATES. 25 
the rough appearance due to the pores and cell walls of the wood. 
The walls of these channels are spotted with little piles of finely 
digested, excreted wood, giving the wood a characteristic mottled 
appearance. 
Large cavities encountered by termites when working in the wood 
of logs, poles, or trees with decayed heartwood or hollow core are 
usually filled up with moist earth mixed with frass, the whole having 
a clay-like consistency and a conglomerate appearance due to the 
irregular deposits of excreted, finely digested wood. The “doty”’ 
hollow cores in the bases of infested poles are filled up in this manner. 
In all their operations the termites carefully wall up and conceal 
themselves. Usually there is but little evidence on the exterior of 
infested wood to indicate the presence of termites, and they may not 
be detected until the interior is completely honeycombed. Sexed 
adults swarming from infested buildings are always a warning of their 
presence. Again, the outer surface is covered over with longitudinal 
viaducts of small diameter constructed of earth (PI. VII, figs. 1 and 2), 
and whereas the interior channel is smooth, the exterior has a rough 
granular appearance. These viaducts are resorted to in order to 
extend the colony or to reach some object, such as decayed wood, or 
when their pathway crosses some impenetrable substance, the object, 
of course, being always protection from the light—all except the 
winged sexed adults shun the light—and their numerous enemies. 
Viaducts, or “sheds,” can be seen running up to a considerable height 
above the ground in the longitudinal weathering checks on poles and 
posts, as well as between the crevices in the bark of infested dead 
and living trees, and uncovered viaducts are found under the loose 
bark on dead trees. Viaducts in the interior of hollow-cored poles or 
trees may be of large diameter and may consist of several irregular 
longitudinal interior channels. 
Termites sometimes resort to another type of viaduct, which for 
descriptive purposes may be called suspended tubes. On May 26, 
1912, at Elkins, W. Va., Dr. A. D. Hopkins found termite tubes of earth, 
5 to 6 inches long, hanging from the end of a Virginia scrub pine 
sapling which had fallen, leaving the broken base 2 feet from the 
ground. ‘The termites had evidently infested the base of the sapling 
through the ground before it fell and were trying to make connection 
with the ground by means of these suspended tubes. (Figs. 7 and 8.) 
These covered viaducts or sheds, the uncovered viaducts, and the 
tubes—all constructed by termites of earth and excreted wood—are 
fragile. 
NUMBER OF INDIVIDUALS IN COLONIES. 
Young colonies of Leucotermes flavipes—that is, colonies but 
recently established, in decaying wood or in the ground under decay- 
ing wood, by sexed couples that have swarmed—are small, and since 
the rate of egg-laying by the young queens is remarkably slow, the 
