[Vol. 2 



776 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



the 



lated genus. She concluded that the carbohydrates existed in 

 the form of hemicelluloses, probably as pentosans. 



Glycogen, although frequently found in the "blue-greens," 

 where, as held by some authors (Fischer, '05), it functions 

 as the chief reserve carbohydrate, has been demonstrated in 

 but one case, as far as is known, in the Chlorophyceae, and 

 that by Beyerinck ('04) in Chlorella variegata. 



Simple sugars. — The nature of the simple sugars in 

 group is indefinite. Klebs ( '96) reported a substance in the 

 cells of certain Heterokonteae that reduced Fehling's solu- 

 tion, but this means little since most algae contain non- 

 carbohydrate reducing substances made up chiefly of tannins 

 and tannoidal bodies. Tihomirov ('10) used the phenyl- 

 hydrazine method as modified by Senft ( '04) for the detection 

 of osozone-forming sugars in algal tissues in this group, 

 chiefly those of Codium bursa and C. tomentosum. After a 

 period of thirty days, for these two forms, yellow amorphous 

 deposits appeared in the cells indicating a sugar reaction. 

 The definite sugars these osozones represented could not be 

 determined, but he suggests the possibility of dextrose and 

 d-galactose. It seems evident that they must be present in 

 very small quantities in the tissues investigated. 



PHAEOPHYCEAE 



Polysaccharides. — Starch is conspicuously absent from the 

 great group of "browns," but there are, however, certain less 

 highly condensed polysaccharides present. Schmiedeberg 

 ('85) speaks of a dextrin-like compound which he isolated 

 from Laminaria. He gave to it the name "laminarin" and 

 the general formula, HKCeOioOs^EkO. There seems, how- 

 ever, to be some confusion regarding his method of arriving 

 at these figures. Torup ('09) was able to extract a dextrin 

 from Laminaria sp. with warm water, that gave dextrose on 

 hydrolysis. This could be isolated only during the winter 

 months. He called it "kreftin." Kylin ('13), extracting 

 crushed Laminaria saccharina, Fucus vesiculosus, and Asco- 

 phyllum nodosum, obtained a dextrin-like compound similar 

 to that described bv Schmiedeberg and he retained Schmiede- 



