340 



Philippine Journal of Science 



cellulose, namely, lignocellulose. Lignin, like cellulose, consists 

 of three elements — carbon, hydrogen, and oxygen — but in dif- 

 ferent proportions, its percentage composition being C 49, H 6, 

 44. Its chemical constitution is as yet unknown. It is harder 

 and more elastic than cellulose, readily permeable by water, 

 but not absorbent. It is more soluble in acids than is cellulose 

 and is recognized by turning deep magenta when treated with 

 phloroglucinol in hydrochloric acid. 



As shown in the preceding pages, Coptotermes formosanus 

 seriously injures all sorts of woodwork and wood products. 

 However, why it attacks such materials or, in other words, what 

 was the principal food of Coptotermes formosanus contained in 

 wood was quite unknown. In order to settle this question the 

 following experiments were made: 



Experiment 1. — A living worker or soldier of Coptotermes 

 formosanus was placed on a microscope slide, and the tip of 

 its abdomen was pressed, the excrement being thus discharged. 

 This was treated with phloroglucinol in hydrochloric acid under 

 a cover glass. The color changed to deep magenta, showing 

 the characteristic reaction of lignin. • 



Experiment 2. — A piece of the nest was treated with the same 

 reagent. It also gave a deep magenta coloration, characteristic 

 of lignin. 



Experiment 3. — A piece of camphor wood and a nest of Copto- 

 termes formosmius made from camphor wood were analyzed. 



Table VI. — Composition of camphor wood and of a nest of Coptotermes 

 formosanus. Analyzed by T. Katayama, 



[Numbers give percentages.] 





Water. 



Ash. 



Aqueous 

 extract. 



Pen- 

 tosan . 



Cellulose. 



Noncel- ; 



lulose. '■ 





11.51 

 11.39 



13.87 



1.29 

 17.86 



0.00 



4.53 

 4.83 



5.88 



13.92 

 6.02 



7.33 



48.35 

 12.73 



15.50 



20.40 1 

 47.17 



•67.42 



Nest 



N«st (calculated as a substance 

 withnoauh) 



It is quite obvious that the amount of cellulose is the main 

 difference between the constituents of the camphor wood and 

 those of the nest. As there occurs no decrease of noncellulose, 

 it is clear that cellulose has been taken as the food when the 

 camphor wood passed through the alimentary canal; and non- 

 cellulose, that is, lignin, which is produced as a decomposed 

 material of lignocellulose by the special function of the alimen- 

 tary canal, is discharged as the building material of the nest. 



