1915] 
DAVIS—ENZYME ACTION IN MARINE ALGAE 805 
acid (sp. gr. 1.1). The flask was kept in the ice-box for two 
weeks, when the oxidizing mixture was changed and the new 
lot allowed to remain another fortnight. At the end of this 
time a yellowish white tissue was obtained, representing fairly 
pure algal cellulose. This was filtered off, washed well with 
distilled water, and dried in the oven at 75-80°C. The final 
product weighed 19.7 grams. 
This cellulose was used in a way similar to the filter paper 
in the first series. One gram was placed in each flask and well 
shaken up with 50 cc. of distilled water. A concentrated 
‘‘diffusion-extract’’ was prepared from Ascophyllum, Lamin- 
aria, Ulva, and Chondrus, 10 ec. of which represented 5 grams 
of the original dried tissue. This volume was added to the 
flasks, and the series set away at 30°C. with toluene as an 
antiseptic. At the end of two months no reduction of Fehl- 
ing’s was observable and under the microscope there seemed 
to be no decomposition of the cellulose particles. 
Action on hemicelluloses—Hemicellulose was used from 
two sources—from date seeds, and from the seeds of the wild 
persimmon, Diospyros virginiana. In both cases the experi- 
ments were essentially the same. The horny coats were 
broken and the embryos removed. Small pieces of the hemi- 
cellulose were then taken, placed in a flask with water, and 
heated in the autoclave at 15 pounds for 15 minutes to kill 
the cytase present. Upon removal from the autoclave the 
pieces were washed several times in distilled water, being left 
in the last wash water for several days with toluene as an 
antiseptic—this to get rid of any reducing sugars present. 
Two of these washed pieces were placed in test-tubes with 
10 cc. of the concentrated ‘‘diffusion-extract’’ used in the ex- 
periments with cellulose. Another lot was covered with 10 ce. 
of distilled water and 2 grams of the dried algal powder 
added. In a third series shavings of the hemicelluloses were 
mounted in a Van Tieghem cell with a drop of enzyme solu- 
tion. All the algae under investigation were tried out, but in 
no case was there the slightest trace of decomposition, either 
microscopically or by the reduction of copper. 
