866 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Albumen, Nuclein, and Plastin.* — For demonstration of the 

 presence of proteids within the cell, E. Zacharias employs their 

 property of giving a precipitate with acid solution of potassium ferro- 

 cyanide. For this purpose he employs a mixture of a solution of 

 1 part of potassium ferrocyanide in 10 parts of water, with 2 volumes 

 of a solution of acetic acid of sp. gr. 1 • 063 in its own volume of 

 water, washes with dilute alcohol of 60 per cent., and then places the 

 cells in a solution of chloride of iron. The potassium ferrocyanide, 

 which forms a compound with albumen insoluble in water, enters into 

 mutual decomposition with the chloride of iron, and all the pro- 

 teiuaceous parts of the protoplasm are coloured blue. Although this 

 reaction does not indicate with certainty the presence of albumen, 

 failure is a certain proof of its absence. The nuclein and nucleoli 

 of the nucleus, and the starch-generators of the epidermal cells of 

 the leaf of Orchideae, are coloured blue. The author concludes that 

 a large portion of the substance of the starch- generators is composed 

 of albumen. Albumen also occurs, though in smaller quantities, in 

 the chlorophyll-grains of Samhucus and Orchis. 



The application of this reaction to dying leaves proves, to the 

 satisfaction of the author, that the decrease in the amount of nitrogen 

 contained is due to the diminution of the amount of albumen, more 

 than of the other nitrogenous constituents of the cell. 



Chemical Changes in the Germination of Barley, t — K. Michel 

 states that in the germination of barley grains there is a loss of 

 starch to the extent of 10 per cent., a portion being converted into 

 carbonic acid and water, and a smaller portion into dextrin and sugar. 

 From the albuminoids two important ferments, diastase and peptase, 

 are formed very rapidly. As the radicle developes, further changes 

 take place in the nitrogenous constituents of the seeds, substances 

 being produced of the nature of amides, the proportion of acids 

 increasing at the same time. 



Function of Amygdalin in Germination.t — It has long been 

 known that amygdalin occurs in the bitter almond, associated with a 

 special ferment called emulsin or synaptase, which, in the presence of 

 water, decomposes it into glucose, benzoic aldehyde, and hydrocyanic 

 acid ; while the sweet almond contains also emulsin, but only a small 

 quantity of amygdalin or none at all. The evolution of hydrocyanic 

 acid characterizes the germination of many other seeds; and A. Jorissen 

 now shows that this is also the case with flax seeds under certain 

 conditions. If soaked in warm water, then exposed for a time to a 

 temperature of 25° C, and distilled, the water distilled off contains 

 hydrocyanic acid. This acid does not exist as such in the seeds of 

 the flax, any more than in the bitter almond, but is the result of the 

 action upon amygdalin of a substance analogous to emulsin. The 

 purpose of the amygdalin, as of other glucosides, appears to be to 



* Bot. Ztg,, xli. (1883) pp. 209-15. 



t SB. Bot. Ver. Miinchen, May 9th, 1883. See Bot. Centralbl., xv. (1883) 

 p. 91. 



I Bull. Acad. K. Sci. Belg., v. (1883) pp. 750-7. 



