206 L. R. CLEVELAND. 



the principal color-forming aldehyde of wood is coniferyl alde- 

 hyde. Cross and Doree (1922) conclude: "We have thereform 

 a direct confirmation of the view that the color reactions of lig- 

 nocellulose are those of derivatives and associated furfural 

 products." 



When tested with aniline acetate most of the wood ingesting 

 protozoa are colored yellow, which coloration is probably brought 

 about by the presence of methylfurfuraldehyde (Cunningham 

 and Doree 1914). When tested with the same chemical, at the 

 same time, a small percentage of the wood ingesting protozoa 

 and many of the wood particles free in the termite's (Termopsis] 

 intestine are colored pink, which coloration is probably brought 

 about by the presence of a trace of furfuraldehyde, for Cross and 

 Doree (1922) state that "the aniline acetate test differentiates 

 the aldehydes." Wood, before being ingested by the termites 

 gives the same pink color reaction to phloroglucinol and hydro- 

 chloric acid that appears inside the bodies of the protozoa. Also, 

 aniline acetate reacts with uningested wood in the same way that 

 it does with the wood particles inside the bodies of the wood in- 

 gesting protozoa and the wood particles free in the intestine. 



Now, what does the phloroglucinol reaction show? \Vhat is 

 its value? It may show that the reacting substance (the substance 

 producing the coloration) is a derivative of lignocellulose or a 

 substance associated with lignocellulose. If the reacting sub- 

 stance is a derivative of lignocellulose, the lignocellulose bond or 

 linkage has perhaps been broken, and it is highly probable that 

 the protozoa are responsible for the breaking of it. Not many of 

 the wood particles free in the intestine exhibit this reaction, and 

 it is possible, of course, that the particles which do react have been 

 inside the bodies of the protozoa. If the reacting substance is 

 an aldopentose, as Buscalioni and Comes (1910) thought it was, 

 it may be that the linkage or bond between aldopentoses and 

 cellulose (Sherrard 1922) has been broken and, if so, it is highly 

 probable that the protozoa have broken it. But, since the wood, 

 before being ingested by the termites and reingested by the 

 protozoa, gives the same color reaction that it does after inges- 

 tion, it is perhaps best to suspend judgment until more is known 

 regarding the specificity of the phloroglucinol reaction. 



However, the clear-cut, definite, and unmistakable glycogenic 



