1915] 
DAVIS—ENZYME ACTION IN MARINE ALGAE 775 
the diastase and maltase of the barley grain, or they may only 
arise when there is food transformation and translocation, as 
in germinating seeds. However, in the light of such possi- 
bilities of association, it is worth while to call attention briefly 
to some of the work that has been done on the chief storage 
products of the algae. 
The carbohydrates have been more worked over in this 
respect than has any other chemical group, but much confusion 
still exists regarding their exact status in assimilation. Much 
of the study has been on the cleavage products, obtained by 
acid hydrolysis, of undetermined carbohydrates. These, how- 
ever, are not a true index of the distribution and more re- 
stricted chemical nature of assimilable carbohydrates in the 
living plant; one must look rather to the work of those who 
have limited themselves to the isolation and determination of 
unaltered carbohydrates. 
CHLOROPHYCEAE 
Polysaccharides.—Nageli (’63) reported ‘‘spharokristalle”’ 
in Acetabularia which Leitgeb (’87) later showed were inulin. 
The former worker also demonstrated the presence of this 
carbohydrate in various members of the Dasycladaceae. 
Kiister (’99) has more recently found characteristic crystal 
formations in Derbesia and Bryopsis which, from the many 
reactions they gave, appear to have been inulin. Famintzin 
(767) and Krause (’70) worked on the effect of light on 
starch formation in Spirogyra, and within recent years, Tim- 
berlake (’01) has contributed observations on the starch of 
Hydrodictyon. Oltmanns (’05, p. 147) speaks of starch ac- 
cumulation in the Conjugales, Volvocales, Ulotrichales, 
Charales, Siphonocladiales, and some of the Siphonales. He 
considers it the first visible product of assimilation, but 
thinks that it may also function as a reserve. Starch in the 
marine forms seems to be quite widely distributed. In the 
work of Arber (’01), to which reference has already been 
made, starch accumulation in the tissues of Ulva, Cladophora, 
and Enteromorpha was easily demonstrated by means of 
iodine. Swartz (’11) isolated starch from Ulva but was 
unable to prove its presence in Enteromorpha, a closely re- 
