144 BOTANICAL GAZETTE [FEBRUARY 
2. DIGESTION IN VAN TIEGHEM CELLS 
' The cells were examined daily and it was found that in those 
containing the starch treated with the algal extracts, very notice- 
able corrosion of the grains was taking place. The rates of 
digestion agreed very well with the tabulated results in table V, 
Polysiphonia and Agardhiella acting more rapidly than Ceramium. 
The results thus obtained in the first trial were confirmed by repeat- 
ing the experiment several times. Marked acceleration of cor- 
rosion was obtained by placing the cells in a warming oven at a 
temperature of 26° C. No corrosion could be detected in the 
control cells. 
Discussion 
That the disappearance of the starchlike grains in the living 
tissues of the red algae is due to the presence of some catalytic 
agent, which may be extracted and applied to corn starch and its 
derivatives with positive effects, is demonstrated by the results 
recorded in the foregoing tables. The action of this extract when 
applied to starch paste is very similar to that of commercial dias- 
- tase. This is shown by the fact that in both cases the digestion 
of the starch appeared to be a series of processes leading more or 
less gradually from the amyloses down through the dextrins until 
amylolytic action was complete. This is brought out clearly not 
only by variations in color, but also by the fact that often when 
the iodine would indicate a marked degree of change in the solu- 
tion, still the Fehling’s test would show the presence of but very 
little sugar. It would appear from this that the algal extract, like 
the diastase of the higher plants, is not one simple enzyme but a 
complex of amylases and dextrinases. Then, if we may argue 
from analogy, the grains in the red algae, commonly referred to as 
starch, are probably, as Meyer’ and others suggest, a combination 
of both starch and dextrins, or, as Btrscuir® thinks, possibly a 
transitional stage between amyloporphyrin and amyloerythrin. 
No direct evidence was obtained by experimentation as to 
whether or not this carbohydrate-digesting enzyme of the red algae 
7 MEYER, A., Untersuchungen iiber die Stirkekérner. Jena. 1895- 
8 Birscuut, O., Notiz iiber d. sogen. Florideen Starke. Verh. Naturf. Med. Ver. 
Heidelberg N.F. 7:519-528. 1903. 
