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778 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Hansteen. He holds that none of these are to be considered 

 the first visible products of assimilation, and suggests that 

 here, as in most phanerogams, carbohydrates function in that 

 role. 



Simple sugars. — As far as is known, Tihomirov ( '10) was 

 the first to definitely demonstrate simple sugars in these 

 plants. He used the same phenylhydrazine method employed 

 with the' 'greens," but as was the case there, was unable to con- 

 nect the osozones with definite sugars. The osozones took con- 

 siderable periods of time to form, in some cases as long as five 

 months, evidence pointing to the low concentration of sugars 

 in the cell. It is a question, too, whether during this long 

 period of incubation some of the more highly condensed carbo- 

 hydrates in the cell were not hydrolysed far enough to give 

 the sugar tests. Using the same method, Kylin ('13) was 

 unable to substantiate these results. However, by using 40 

 per cent alcohol as an extracting agent, precipitating the in- 

 organic material with lead acetate, and then purifying with 

 alcohol, he was able to obtain reducing sugars from several 

 of the Fucoideae, particularly Laminaria digitata, L. sac- 

 charina, Ascophyllum nodosum, and Fucus vesiculosus. In 

 all cases Seliwanoff's test for fructose was positive, while 

 dextrose was demonstrated by its osozone. These sugars he 

 considers the first products of assimilation referred to above. 



RHODOPHYCEAE 



Polysaccharides. — The so-called Florideae-starch has been 

 the source of many investigations, from the time of Nageli 

 ('58) and Van Tieghem ('65) to the present day. Although 

 not identical perhaps, it is very similar to the starch of the 

 higher plants, and as very generally held, it undoubtedly func- 

 tions in the same manner. Meyer ('95), Kolkwitz ('00), 

 and Bartholemew ('14) hold the opinion that it repre- 

 sents a combination between true starch and dextrin, 

 while Biitschli ('03) suggests the possibility of its being a 

 transitional stage between amyloporphyrin and amyloery- 

 thrin. Kylin ('13) considers it as standing midway between 

 starch and dextrin. This investigator succeeded in isolating 



