THE RESERVE MATERIALS OF PLANTS. 



(Continued.) 



IN addition to the nitrogenous matters already described 

 as occurring in plants, a curious body of proteid 

 character can be extracted from the ground seeds of 

 several of the cereal grasses, the exact nature of which 

 has given rise to a good deal of controversy. This body, 

 which is known as gluten, can be prepared easily from 

 wheat flour by washing it on a muslin filter. The starchy 

 matters and various soluble bodies pass through ; a curious 

 sticky material is left clinging- to the muslin. No such 

 proteid is found to be present in the uninjured seed, and 

 it appears therefore to be formed during the process of 

 washing the flour. 



Investigations into its nature and its relation to the 

 proteids of the wheat grain have been made by several 

 writers, and a leaning is found to the view that it is a kind 

 of vegetable fibrin, produced by a species of fermentation 

 analogous to that so generally associated with the process 

 of the coagulation of the blood. In the light of this discussion 

 considerable interest attaches to some investigations into 

 the proteids of the seeds of the cereal grasses, particularly 

 wheat and rye, carried out last year in the laboratory of 

 Professor Chittenden, by Messrs. Osborne and Voorhees 



(19). 



These observers have made a careful analysis of the 

 constituents of the uninjured flour, in which they have 

 confirmed and extended the researches of older writers. 

 They find the wheat grain to contain five distinct proteids, 

 of which three can be classified as members of the already 

 well-known groups, while two others have special peculiari- 

 ties as to solubility in fluids which do not attack the 

 former three. The latter are a globulin, an albumin and a 

 proteose. 



The globulin, which the authors name Edestin, is a 

 member of the vitellin section of the group, characterised 



