300 Mary Davies Swartz, 



Excluding the experiment of Luchsinger (310) which was estimated 

 on a very low specific rotation for glycogen, only four out of the 17 

 experiments before Miura's (313) are positive, and in these the gly- 

 cogen was estimated without purification, so that the figures are prob- 

 ably high. In more reliable experiments of Miura (313), and Mendel 

 and Nakaseko (312), the glycogen content of the rabbits' livers was 

 as low or lower than the starvation maximum for the rabbit, as esti- 

 mated by Kiilz (309), so that glycogen formation from inulin must be 

 regarded as doubtful, or very slight. 



When inulin is introduced par enter ally into the organism, there is 

 no inversion or utilization, as shown by the experiments of Mendel 

 and Mitchell (311). They injected warm solutions into the peritoneal 

 cavity, and determining the output of inulin in the urine (which was 

 sugar-free) by calculations from the specific rotation, recovered 2.2 

 grams of 2.8 grams injected. In an experiment in which the sugar- 

 free urine was hydrolyzed, and the output of inulin calculated from 

 the amount of reducing sugar obtained, 1.43 grams were recovered 

 out of 2.2 grams injected. Weinland (326) after subcutaneous injec- 

 tions of inulin into dogs, continued for a month, found no inulase 

 produced thereby. On the other hand, Saiki (316) succeeded in pro- 

 ducing a definite anti-inulase in rabbit's serum. 



We see, therefore, that inulin is not attacked by animal enzymes, as 

 far as investigated, with the possible exception of two species of inver- 

 tebrates; and by a very few vegetable enzymes. It appears to a con- 

 siderable extent in the faeces after being fed per os in spite of the abil- 

 ity of the gastric juice to hydrolyze it. In spite of the accepted fact 

 that levulose is capable of being directly utilized by the animal body 

 there is no conclusive evidence of glycogen formation from inulin. 

 Whether other levulans resemble this hemicellulose in these respects 

 has not been investigated. 



Occurrence and Nature of Dextrans. 



In the higher plants, starch, dextrin, and cellulose occur almost to 

 the exclusion of other anhydrides of dextrose. A few hemicelluloses 

 yielding dextrose have been described, however, such as "a-amylam" 

 (soluble in hot water) and "/3-amylam" (soluble in cold water), dis- 

 covered by O 'Sullivan (343) in wheat, rye and barley; those in the 

 mucilaginous extracts of flax-seed and fleabane, described by Bauer 

 (329) and Rothenfusser (345); and that in Colocasia antiquorum, 

 described by Yoshimure (352). 



