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distinguished by the presence of ketohexene groups in union with 

 the cellulose, and therefore combining directly with the halogens. 



Generally, w^alls of cellulose, fibres, and vessels in the wood 

 acquire mechanical strength or resistance by undergoing a change 

 know^n as ligniticatioh. This consists in their impregnation with a 

 substance known as lignin. forming a compound cellulose, namely, 

 lignocellulose. Lignin, like cellulose, consists of three elements- 

 carbon, hydrogen, and oxygen — but in different proportions, its 

 percentage composition being C 49, H 6, O 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 hydro- 

 chloric acid. 



As shown in the preceding pages, Coptotermcs formosanus 

 seriously injuries all sorts of w^oodwork and wood products. 

 However, why it attacks such materials or, in other w^ords, what 

 was the principal food of Coptotermcs formosanus contained in 

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

 following experiments were made : 



Experim:ent 1. — A living worker or soldier of Coptotcnnes 

 formosanus w^as 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- 

 termcs formosanus made from camphor wood were analyzed. 



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

 difference between the constituents of the camphor w'ood 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. 

 (To Be Continued.) 



DIVISION OF FORESTRY. 



REPORT OF SUPERINTENDENT OF FORESTRY, OCTOBER, 1920. 



Honolulu, November 13, 1920. 



Board of Commissioners of Agriculture and Forestry, Honolulu, T. H. 



Gentlemen: — I respectfully submit tlie following routine report of the 

 Division of Forestry for the month of October, 1920: 



