320 Philippine Journal of Science m» 



ausser Eisen und Stein." Such being the case, not only is the 

 extermination of these insects almost impossible, but also pre- 

 ventive measures against their damage are difficult to apply. 



Fortunately, Japan is located in a temperate region; and, 

 therefore, her people have not been obliged to pay attention 

 to these formidable pests. However, one species, Leucotermes 

 speratus Kolbe, which very often causes somewhat serious dam- 

 age to wooden structures, has been recorded in Japan since 

 1724. About twenty years ago, Japan occupied Formosa, which 

 lies in a semitropical region; that is, in the western Pacific 

 Ocean, between the southern and eastern China Seas. In 

 this possession the people have been compelled to fight against 

 the common pest of the Tropics, and the investigation of the 

 biology of termites has become one of the most important prob- 

 lems of the architect and the entomologist. 



In Formosa and in Japan there are fourteen species of ter- 

 mites, four of which, namely Coptotermes formosanus, Leuco- 

 termes speratus, Leucotermes flaviceps, and Odontotermes for- 

 mosanus, are known as pests of wooden structures. Coptotermes 

 formosanus, which is distributed in Formosa, Riu Kiu Islands, 

 and in the southern parts of Japan proper, is especially formid- 

 able to buildings. It is certain that the other three attack 

 woodwork, and wooden structures as well, but their ravages 

 are negligible in comparison with those of Coptotermes for- 

 mosanus. 



During the last ten years, I have been investigating the 

 Japanese termites, especially the habits of Coptotermes formo- 

 sanus. I approached the problem of the method for preven- 

 tion with the following ideas as a working basis : 



1. Some changes are necessary with regard to the construction of build- 



ings in the Tropics in order to prevent damage by termites. 



2. The value of termite-proof building construction is not absolute, 



unless all sorts of nonresistant timbers are eliminated from the 

 building materials. 



3. If it shall be proved that the elimination of nonresistant timbers 



is practically impossible, it becomes necessary to treat them chemi- 

 cally or physically in order to confer a special resistant property. 



4. It is necessary to prove whether or not there are naturally resistant 



timbers in the Tropics. 



5. If there are naturally resistant timbers, an investigation with the 



object of discovering the cause of resistance becomes important. 



6. If the causes are definitely known, methods of artificially treating 



nonresistant timbers will be more easily discovered. 



By the kind and valuable assistance of Mr. Kinzo Kafuku. 

 former expert chemist of the Government Institute of Science, 



