The Typical Cellulose and the Cellulose Group 87 



of the cereals and of leguminous plants. It appears, therefore, 

 generally that a large number of plant constituents which have 

 been denominated by the physiologists as 'Cellulose' have 

 little more title to be considered as such than has starch. 

 However, external resemblances count for something, at least in 

 the beginnings of classification, and substances of the type we 

 are considering may be conveniently grouped with the cellu- 

 loses ; but we should propose to apply to them the term 

 PSEUDO-CELLULOSES, or HEMICELLULOSES as has been pro- 

 posed by E. Schulze. Our group (c) of pseudo-celluloses may 

 therefore be defined as Substances closely resembling in 

 appearance the true celluloses, but easily resolved into simple 

 carbohydrates by the hydrolytic action of enzymes, or of the 

 dilute acids and alkalis. 



Animal Celluloses. Tunicin a compound of the em- 

 pirical composition of cotton cellulose, and resembling it in a 

 number of its properties and reactions is isolated from the 

 mantle of Ascidia and other invertebrate species by exhaustive 

 hydrolytic treatments. Such resistant residues have been in- 

 vestigated by Schmidt (Annalen, 54, 318), Berthelot (Compt, 

 Rend. 47, 227), Lowig and Kolliker (J. Pr. Chem. 39, 439), 

 Schafer (Annalen, 160, 312), and more recently by Franchimont 

 (Compt. Rend. 89, 755). From these later investigations it 

 appears that the sugar obtained as the product of ultimate hydro- 

 lysis is identical with the dextrose obtained from the vegetable 

 celluloses. From this and its reactions generally, which differ in 

 some respects from those of the normal cellulose, Franchimont 

 concludes that the compound is undoubtedly a cellulose, but 

 of different constitution from the normal. Cellulose has also 

 been identified as a constituent of the protozoa. Investigations 

 of one of these organisms Ophrydium versatile by Halli- 

 burton showed the investing matrix of a colony of these ciliated 



