338 
Philippine Journal of Science 
1919 
mortar of brick walls vast numbers of soldiers are found. Such 
being the case, it is said that the soldier of Coptotermes formo- 
sanus attacks lime mortar by dissolving the lime with the 
acidulous secretions. 
Damage to railway sleepers. — Coptotermes formosanus attacks 
railway sleepers^ as well as buildings. According to a state- 
ment of the Bureau of the Formosan Government Railway, the 
life of an untreated, chestnut sleeper is only two years in For- 
mosa, while in Japan proper it is from eight to ten years. 
In the southern part of Formosa another species of termite, 
Odontotermes formosanus, also attacks the sleepers, as shown 
in Plate VIII, fig. 3. The damage it causes is rather more 
serious than that caused by Coptotermes formosanus. There- 
fore, in the case of sleepers, it is important to prevent the 
damage caused by these two species. Usually the length of the 
spike which is used to fix the rail to a sleeper is a little greater 
than the depth of the latter, so that its tip always penetrates 
beyond the bottom of the sleeper, causing some damage to that 
surface (Plate VIII, fig. 1). This point is most liable to be 
attacked. As the pests excavate the wooden tissue surrounding 
the spike (Plate VIII, fig. 2), the latter becomes ineffective. 
Suppose such damage occurs successively in several sleepers; 
the results are quite obvious — the rails spread and cause great 
danger to passing trains. 
Damage to ships . — One can hardly believe that steamships 
and launches in the water have been attacked by Coptotermes 
formosanus; but it is an undeniable fact. There are many 
records of such cases in the harbor of Keelung, Formosa. It 
happens in this way. In the swarming season, many thousands 
of winged males and females start from the nests in the vicinity 
of the shore. Some of them have a chance to fly into the 
ships moored in the harbor and there start new colonies. The 
interior of the ship is dark enough to favor the establishment 
of a nest. Usually the bottom of the ship is constructed of 
Japanese pine, which is most durable in water; all the timbers 
contain a favorable amount of water. Thus, all conditions being 
exceedingly favorable to Coptotermes formosanus, the ravages 
are extended step by step, until the vessel becomes unseaworthy, 
because of the unexpected destruction of important parts of 
the woodwork. In such a case extermination of the pests is 
very difficult. When the Government trawler Ryokai-maru was 
found to be infested, it was purposely sunk in the sea in order 
to destroy the insects. 
