388 



Dr. S. H. Vines. 



[May 13, 



II. The Aleurone- Grains of the Peony (Peeonia officinalis). 



a. Microscopical Observations. — In accordance with the researches 

 of Pfeffer (" Jahrb. f. wiss. Bot.," viii, 1872), the grains were found 

 to be readily soluble in distilled water, the only proteid substance 

 remaining in the cells being the matrix, which, like that of the lupin, 

 is insoluble in dilute acids and alkalies. They also dissolve in 10 per 

 cent, and in saturated NaCl solutions. Their solubility is unaffected 

 by previous treatment with either ether or alcohol. 



b. Chemical Observations. — The watery extract of the seeds (which 

 has only a very faint acid reaction if a relatively large quantity of 

 water is used) becomes turbid on boiling, and it gives all the reactions 

 of a fluid holding proteid substance in solution. If it be boiled, 

 evaporated to small bulk, and then filtered into alcohol, a dense pre- 

 cipitate is formed. The substance precipitated readily dissolves in 

 distilled water, and the solution gives the reactions characteristic of a 

 solution of peptones. The substance does not dialyse. It is probable, 

 therefore, that it is identical with the soluble proteid detected in the 

 seeds of the lupin, which I provisionally termed Hemialbumose. 



This substance is readily precipitated from its watery solution by 

 the addition of a small quantity of acetic acid. The precipitate 

 differs, however, from the original substance in that it is only slightly 

 soluble in distilled water : it is more soluble in solutions of alkaline 

 carbonates, and it dissolves completely in dilute solutions of the 

 alkalies. In this respect it resembles acid-albumin (syntonin) . 



If the seeds, after extraction with water until the filtrate gives only 

 a very faint xanthoproteic reaction, be treated with 10 per cent. NaOl 

 solution, a fluid is obtained which gives a dense precipitate on boiling, 

 a precipitate on dilution with water, and on saturation with ISTaCl. 



Further, if the seeds be extracted with saturated NaCI or MgS0 4 

 solution, a fluid is obtained which gives a slight turbidity on boiling, 

 but no perceptible turbidity on dilution. 



From these observations, it appears that the aleurone- grains of the 

 peony consist of one proteid soluble in water (hemialbumose), and of 

 another, insoluble in distilled water, but soluble in 10 per cent. NaCI 

 solution, and precipitable from its solution by boiling or by saturation. 

 This latter body corresponds in these respects with the substance 

 found in the seeds of the lupin, and termed vegetable myosin. 



It seems probable that the grains of the peony contain no substance 

 (or, at most, a very small quantity of it) analogous to the vegetable 

 vitellin, which occurs in the grains of the lupin, and which is soluble 

 in saturated NaCl solution. 



III. The Aleurone- Grains of the Castor Oil Plant (Ricinus communis) . 

 a. Microscopical Observations. — When mounted in alcohol, the grains 



