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of this insect is insidious, usually leaving the outer layer of wood 

 intact as a protective covering from sunlight and its natural 

 enemies, so that the damage is always hidden until beyond repair, 

 it is a most dangerous enemy to buildings. 



In infesting buildings it generally gains entrance from outdoor 

 colonies. By means of subterranean tunnels of considerable 

 length, which originate from a nest in the ground, it reaches the 

 foundation of a building. At first it attacks foundation timbers, 

 flooring, or supports of porches or steps that are in contact with 

 the ground, and gradually extends its tunnels and excavation into 

 the first, the second, or even the third ffoor and into the roof, 

 passing through the walls or the interior of timbers. 



In cases where the foundation is of stone, concrete, or other 

 impermeable material, it constructs a covered tunnel of a mixture 

 of earth and saliva over the surface and reaches the woodwork. 

 Generally a cross section of this artificial tunnel is semicircular, 

 the diameter being from 5 to 10 millimeters. 



Damage to buildings. — Ordinary Japanese houses are chiefly 

 constructed of wood and clay, the foundation timbers being laid 

 in contact with the ground. Thus the construction itself is not 

 fitted to prevent the attack of termites. Moreover, Japanese 

 pine and cryptomeria, which are most liable to be attacked by 

 Coptotermes formosanits, are the principal building materials. 

 Such being the case, the Japanese people suffer a great deal from 

 the damage when they erect buildings of their own style in For- 

 mosa. 



As the work of Coptotermes formosaiius is hidden, it is dif- 

 ficult to detect the presence of the insects or the damage that they 

 are doing. After they have caused the fall of a building, the 

 beams, the rafters, and other important parts of the woodwork are 

 often found to be mere shells, the interior being entirely honey- 

 combed. 



Damage to brick zcalls. — There are several records in Formosa 

 of modern brick buildings having been infested by Coptotermes 

 formosanus. It is absolutely impossible for it to attack brick 

 itself; but, according to my actual observation, the mortar which 

 is used as a cementing material for bricks is subject to attack. 



In building a thick brick wall the following method is adopted : 

 The face bricks are laid upon a bed of mortar; the mortar, in a 

 semifluid condition, is then poured into the space between the 

 face bricks ; the bricks are then pushed rapidly, horizontally for a 

 short distance, into their position ; a certain amount of the mortar 

 is thus displaced; this rises in the side joints and completely fills 

 all the interstices ; should the mortar not rise to the top of the 

 joints, the vacant spaces are filled up, when the next course is 

 larried. 



■ All the interstices between the bricks woul'd be completely filled, 

 if the bedding could be carried on theoretically ; but this is prac- 

 tically impossible, so that there are almost sure to be voids in 

 brick walls. Under such conditions, termites prefer to pass 



