22 The Botanical Gazette. {January, 
of its properties) made a preparation of glycosamine by the 
method of Ledderhose, and tried it with chlorozinc iodide to 
see whether it gave the blue color, and found that it did not. 
This subtance is dextro-rotatory and reduces Fehling’s so- 
lution as readily as dextrose, and these facts may account for 
the supposed derivation of true dextrose from chitinous tissues 
by the older observers, and hence we have only the work of 
Winterstein on tunicine to prove the existence of true cellu- 
lose in animal tissues. 
In conclusion then, I am inclined to think that Gilson’s test 
for cellulose is a much more satisfactory one than the ordin- 
ary chlorozinc iodide test, and should therefore replace the 
old method in the demonstration of cellulose in vegetable 
tissues in the laboratory. Its use in my hands seems to prove 
that the blue staining substance present in tunicates, arthro- 
pods and certain mollusks is not identical with vegetable cel- 
lulose chemically. 
We must, however, consider the animal substance under 
discussion as possibly quite similar to, perhaps only a slight 
modification of, true cellulose. For as we have seen above, 
the substance of the supporting tissue of the fungi, which as 
we know have arisen from plants that in all probability pos- 
sessed true cellulose, are still as refractory as animal tissues 
when treated with Schweizer’s solvent. 
Fohns Hopkins University, Baltimore, Md. 
