142 Mr Parkin, On a reserve carbohydrate, etc. 



Tsuji 1 has shown that the Japanese food, " namakonujaku," 

 prepared from the root of an Aroid {Conophallus Konjak) consists 

 largely of this mannan. Kinoshita 2 has further. investigated the 

 carbohydrate in the root of the plant itself. Still more recently 

 another Japanese investigator 3 has found it in the leaves of the 

 same Aroid, which he names Amorphophallus Konjak 11 , and has 

 also made the interesting discovery of free mannose in the leaf- 

 stalks of this plant. 



Bourquelot and Herissey 5 have lately shown that the reserve 

 carbohydrates of the seeds of certain leguminous plants, e.g. Cera- 

 tonia siliqua, Trigonella Foenum-graecum, Medicago sativa, consist 

 of a mixture of mannan and galactan or a combination of the two, 

 for the carbohydrate-reserve hydrolyses fairly readily to mannose 

 and galactose. 



The carbohydrate found in Lilium is perhaps identical with the 

 mannan of these previous investigators. Consequently the reserve 

 organs of the following monocotyledons may be considered to 

 contain mannan — species of Orchis and Lilium, and the Aroid, 

 Amorphophallus Rivieri. Further research will very likely prove 

 that it is of much wider distribution in bulbs and tubers. 



Mannose has also been shown to be present in or obtainable 

 from other vegetable matters, where it can hardly be reckoned of 

 nutritive value, such as the wood of conifers 6 , orange peel 7 and 

 probably the glucosides 8 , scammonin and ipomoei'n. 



Hence mannose seems destined to become quite an important 

 sugar in plants. 



1 Tsuji, Bull. Coll. Agric. Imp. Univ. Tokyo, 1894, 2, p. 103. 



2 Kinoshita, Ibid., 1895, 2, p. 205. 



3 Tsukamoto, Ibid., 1897, 2, p. 406. I have not been able to see the original 

 papers but only abstracts in the J. Chem. Soc, 1894, 1896, 1897, and in Land. Vers. 

 Stat., Bd. 45, 1895, p. 433. 



4 This plant is named Amorphophallus Rivieri in the Index Kewensis. 



5 Bourquelot and Herissey, Gomp. Rend, cxxix. 1899, pp. 228, 391. 

 e Bertrand, Ibid., p. 1025. 



7 Flatau and Labbe, Bull. Soc. Chim., 1898, p. 408; Abstr. /. Chem. Soc, 1899, 

 p. 445. 



8 Kromer, Abstracts, J. Chem. Soc, 1893, 1, pp. 423, 482. 



