1880.] On the Chemical Composition of Aleur one- Grains. 61 



and it is not affected by previous treatment of the grains with ether or 

 alcohol. 



b. Chemical Observations. — The seeds were crushed in a mortar, and 

 then treated with either alcohol or ether to remove the oil. 



The watery extract of the seeds gives a slight precipitate on boiling ; 

 the filtrate gives no precipitate on boiling; it gives the reactions of a 

 fluid holding peptones in solution; it also gives a precipitate with 

 HN0 3 . 



The 10 per cent. NaCI extract gives a dense precipitate on boiling, 

 as well as on dilution, and on saturation with NaCl. 



The saturated NaCl extract gives a dense precipitate on boiling and 

 on dilution. 



From these observations it appears that these grains consist of 

 vegetable peptone and of globulins, the one belonging to the myosin, 

 the other to the vitellin group. 



Weyl has shown (" Zeitschr. f. Physiol. Chem.," Bd. I, 1877) that 

 the crystalloids of these grains consist of pure vitellin ; hence the 

 peptone and the myosin must be contained in the ground- substance of 

 the grains. 



General Remarks. 



The investigation of the aleurone-grains of a number of different 

 species of plants has shown that, with a few exceptions mentioned 

 below, they may be classified under the five types which have been 

 described in this and previous communications. I find, contrary to 

 the opinion of Pfeffer (" Jahrb. f. wiss. Bot." viii, 1872), that all the 

 aleurone-grains which I have examined are soluble to some extent at 

 least in water ; they are also all soluble to some extent in 10 per cent. 

 NaCl solution. In the cases which have been described in detail, the 

 grains were found to be completely soluble in this solution, but in 

 others I found that the grains were only partially soluble in it, 

 residue dissolving either in 1 per cent. ]STa 2 C0 3 solution, or in dilute 

 KHO, and therefore consisting of some form of albuminate, which 

 may be regarded as altered globulin. 



The proteid substances detected in the grains may be classified as 

 follows : — 



I. Soluble in distilled water : — 



Vegetable peptone (hemialbumose ?). 



II. Insoluble in distilled ivater : — 



a. Soluble in 10 per cent. NaCl solution. Globulins. 

 («.) Insoluble in saturated NaCl solution, — 



Vegetable myosin. 

 (/3.) Soluble in saturated NaCl solution, after treatment with 

 alcohol, — 



Substance of crystalloids of Ricinus, &c. 



