162 Lichenase 
a chemical supply house, and (8) lichenin prepared and puri- 
fied in this laboratory by the method of Berg (4). The first 
preparation was used only in comparison with one of the other 
preparations. Tests for isolichenin made on the other two 
preparations were uniformly negative (color with iodine). No 
differences were noted in these two preparations when used as 
substrates in the enzyme experiments. As controls of the activ- 
ity of the extracts under investigation, freedom from bacterial 
decomposition, etc., tests were also carried out on other typical 
carbohydrates, inulin, raffinose, sucrose, and starch, for the 
presence of other enzymes. In view of the widespread distribu- 
tion of amylase, it was thought that the absence of amylase 
would be indicative of loss of enzyme activity in the preparation 
of the extract. As an additional control, the tissue extract itself 
was incubated with an amount of water equal to the volume 
of the carbohydrate solution used. This was done in order to 
test for the presence of any polysaccharide (e.g., glycogen) which 
might be present in the tissue and yield a reducing sugar on 
autolysis. Only in the case of two of the mollusks studied (Unio 
gibbosus and Lampsilis luteola) was there found evidence of the 
presence of such a carbohydrate. In the experiments with these 
species comparative tests showed the presence of enzymes which 
acted upon the other sugars also. Control tests with boiled ex- 
tracts were also made in each case. All experiments were car- 
ried out at room temperature, at about 21°C. Toluene was used 
as a preservative. 0.5 per cent solutions of lichenin and 1 per 
cent solutions of the other carbohydrates were tested. Tests for 
reducing sugars! with Fehling’s solution were made after 1, 3, 
5, and 7 days. | . 
The hepatopancreas was chosen for investigation in most of 
the invertebrates studied (Nos. 4 to 18, Table I). In the small 
animals (1, 3, 20, Table I) the entire organism was used, while 
in the earthworm and grasshopper the entire alimentary canal 
was removed for examination. The animals were killed with 
ether, the tissues removed immediately, washed, and ground up © 
1 In a number of experiments the reducing sugar was further identified 
by the formation of the osazone. An osazone crystallizing from the 
hot solution, and identified microscopically as glucosazone, was obtained 
from the tubes showing reduction, but never from the control tubes. 
