1915] 
DAVIS—ENZYME ACTION IN MARINE ALGAE 803 
action was observable, either by reduction of Fehling’s or by 
microscopical examination. 
In the experiments on the hydrolysis of various poly- and 
disaccharides, checks were set up in which the usual amount 
of ‘‘diffusion-extract’’ was placed in distilled water. This 
was to determine the reduction of copper, if any, due to the 
‘‘diffusion-extract’’ itself. In no case was there more than 
a very slight trace that might have been due to other 
causes than enzymic. However, it was thought that a 
self-digestion series would more definitely determine whether 
the hydrolysis of the carbohydrates of the slime could be 
brought about by specific algal enzymes. With this in mind, 
a series was arranged in which the flasks contained 50 cc. of 
a water extract from each of the forms investigated. Checks 
were set up in which the ‘‘diffusion-extract’’ was inactivated 
in the autoclave. Toluene was used as an antiseptic and the 
flasks maintained at a temperature of 22-23°C. for two 
months. Aliquot portions removed from time to time failed 
to show the slightest trace of hydrolysis. 
It will be remembered that Tihomirov (’10) had found 
osozone-forming sugars in the conceptacles of Ascophyllum 
and Fucus that he thought might be dextrose and d-galactose, 
possibly also fucose and arabinose. ‘Thinking that these 
might possibly have arisen from their corresponding an- 
hydrides contained in the conceptacle slime, a self-digestion 
series was set up with an extract from the abscised, crushed 
conceptacles of those two forms. The Fucus was in a fruit- 
ing state. The series were set up in duplicate, one kept at 
room temperature and the other at 32-33°C. Fehling’s test 
showed no hydrolysis after a month. 
Pentosans alone were then used as substrates. Two series 
of flasks for each of the algae investigated were set up, each 
containing a .5 per cent solution of gum arabic.t To one 
series was added 10 ec., to the other 20 ec. of ‘‘diffusion- 
extract,’’ and the flasks placed at room temperature with 
toluene as an antiseptic. No hydrolysis was apparent either 
1The gum arabic was dissolved in water, then precipitated with several 
volumes of 95 per cent alcohol to get rid of reducing sugars. 
