220 On the Chemical Composition of Aleurone Grains. [Dec. 19 5 



adopting Kfihne's nomenclature (" Verhandl d. Nat.-Med. Yereins zu 

 Heidelberg," Band I, 1876), the substance to which, he gives the name 

 of Hemialbnmose ; a name which may be provisionally applied to this 

 substance also. 



The proteids stored up in the seeds of the blue lupin are therefore 

 of two kinds : 



(1.) Hemialbumose — soluble in distilled water. 



(2.) Globulins — insoluble in distilled water, but soluble in 10 per 

 cent, NaCl solution. 



In order to determine the exact distribution of these substances in 

 the cells of the seed, I made a series of micro- chemical observations. 

 Thin sections of the cotyledons were placed for a few minutes in ethei 

 and theu in absolute alcohol, in order to remove the fatty matters 

 present which would otherwise interfere with the observation. A 

 section examined in a drop of absolute alcohol shows the cells filled 

 with aleurone grains lying in the meshes of a delicate matrix. They 

 are hyaline or faintly granular, and have a yellowish tint. On adding 

 a few drops of distilled water the grains become coarsely granular ; 

 the granules gradually disappear, and then vacuoles make their appear- 

 ance. Further treatment with water produces no apparent change. If 

 now a few drops of 10 per cent. NaCl solution be added, the hyaline 

 vacuolated grains at once disappear, and nothing remains in the cells 

 (when the section is very delicate) but the network of the matrix. A 

 precipitate may be produced in the fluid under the cover-slip by 

 diluting it with distilled water. The precipitate assumes the form of 

 rounded drops of a viscous nature which are readily redissolved on the 

 addition of NaCl (vegetable vitellin). If the section be irrigated with 

 10 per cent. NaCl solution until the addition of distilled water pro- 

 duces no precipitate, and if it be then well washed with distilled 

 water nothing remains within the cells but the matrix. This is ren- 

 dered conspicuous by adding a drop of solution of iodine which gives 

 it a bright yellow colour. 



It is well known that aleurone grains consist essentially of proteids, 

 but the nature of these proteids has not as yet been determined. From 

 the foregoing observations it appears that at least one proteid is pre- 

 sent which is soluble in water, and one which is insoluble in water but 

 soluble in 10 per cent. NaCl solution. The preceding chemical expe- 

 riments suffice to prove that the former is hemialbumose, and that the 

 latter includes the two forms of vegetable globulin. 



My observations on the solubility of the aleurone grains of the blue 

 lupin in water agree in the main with those of Pfeffer (" Unters. fiber 

 Protein-Korner, &c. Jahrb. f. Wiss. Bot.," Band VIII, 1872, p. 447), 

 but I have been unable to discover that, as he asserts in the case of 

 Pasonia and Cynoglossum at least, long continued exposure to alcohol 

 diminishes their solubility in water. Such treatment affects neither 



