Nutrition Investigations. 283 



Another species of marine algae in which galactan has been fully 

 identified, is Chondrus crispus (Irish moss). This is also a red alga. 

 C. Schmidt (210) first examined it, in 1844; he demonstrated that 

 the gelatinizing substance was a carbohydrate and yielded sugar on 

 hydrolysis. Fluckinger and Mayer (178), in 1868, discovered that 

 the water extract of this alga yielded considerable mucic acid. In 

 1875, Bente (171) obtained levulinic acid from the products of its 

 hydrolysis, and in 1876, reported that it yielded a non-crystallizing 

 syrup (172). The first quantitative analysis was made by Hadike, 

 Bauer and Tollens (185), who showed that the water extract yielded 

 mucic acid corresponding to about 25 per cent of galactan. Sebor 

 (220), in 1900, found in the products of hydrolysis, glucose, fructose 

 and a small quantity of pentose. These observations were verified 

 by Miither (200) in 1903, who further identified the galactose as a 

 J-galactose. From the large yield of mucic acid, the water extract 

 of Chondrus may therefore be regarded as chiefly galactan, together 

 with some dextran and levulan, and a very little pentosan; groups 

 which, according to Hadike, Bauer and Tollens (185), may be partly 

 or entirely bound into ester-like compounds. 



Examples of galactans occurring in combination, or close associa- 

 tion with other hemicelluloses are numerous. Lupeose, from luzerne 

 seeds, originally called /3-galactan, yields 50 per cent galactose and 50 

 per cent fructose (214). The tuberous roots of Stachys tuber if era 

 contain a soluble crystallizable carbohydrate yielding 37 per cent 

 mucic acid, along with an unidentified sugar (225). Para-galactan 

 (galacto-araban) forms a large proportion of the reserve material of 

 many seeds.i Rothenfusser (204) finds that the mucilaginous extract of 

 flaxseed yields equal parts of pentosans and hexosans, the latter being 

 mainly galactose. Galactans and pentosans, as already indicated,* 

 occur together in many lichens and algae, and also in the pectins.' 

 Herissey (187) has shown that the "galactine" of Miintz (199) yields 

 equal parts of galactose and mannose. Galacto-mannans also fre- 

 quently occur in the reserve material of seeds, as in those of the date 

 and other species of palm, and in coffee beans; in the American honey 



iCf. Schulze (215), Schulze, Steiger and Maxwell (217), Schiilze and Castoro 

 (218), Castoro (176), and Goret (179). Also Schulze and Godet, Zeitschrift fur 

 physiologische Chemie, V. 61, p. 279, for a verj^ complete review of the work of 

 Schulze and his pupils. 



^See Chemical Nature of Lichens and Algae:- Konig and Bettels (8), Escombe (6), 

 K. Muller (11), Ulander (26). 



^Cf. Pentosans, p. 268. 



