456 SUMMARY OF CURRENT RESEARCHES RELATING TO 



number of other plant structures, such as sweet potato, pulp of banana, 

 cherry-tree and other gums. 



J. H. Kastle and A. S. Loevenhart * have also investigated the nature 

 of the oxidising ferment, and arrive at the following conclusions : — 

 Oxygen is absolutely essential to the production of the guaiacum-bluing 

 ferment of the potato, and this so-called oxidising ferment is in all 

 probability not a free soluble ferment, but an organic peroxide. They 

 suggest that the oxidation phenomena occurring in the plant, and pro- 

 bably in the animal organism also, can be satisfactorily explained upon 

 the supposition that the readily autoxidisable substances which they 

 contain are oxidised to the peroxide condition by molecular oxygen, 

 and that the peroxides thus formed in turn give up part of their oxygen 

 to other less oxidisable substances present in the cell. 



Action of Sunlight on Enzymes.f — 0. Emmerling has studied the 

 action of sunlight on 1 per cent, solutions of invertase, yeast-maltase, 

 maize-glucase, lactase, emulsin, and diastase. The solutions were ex- 

 posed for six hours, and their fermenting properties then tested, when 

 it was found that, with the exception of yeast-maltase, the enzymes had 

 suffered but very little deterioration. Toxins, on the contrary, appear 

 to be very susceptible to light. 



Transformation of Proteids during Germination.}— G. Andre has 

 studied the nitrogenous metabolism in the haricot beau, comparing the 

 total amount of nitrogen, and of nitrogenous substances in the dry seed, 

 and at various stages in the young seedling, up to the time when the dry 

 weight of the latter equals that of the dry seed. Of the proteids, the 

 albumin, which in the seeds used represents only 2*5 p.c. of the 

 total weight, disappears most rapidly, in fact directly germination and 

 loss of dry weight begin. Legumin, which represents one-fourth of the 

 total nitrogen of the resting seed, also diminishes rapidly, but without 

 completely disappearing. The amide nitrogen (asparagin and allied 

 bodies) which remains in solution after separation of the albumin and 

 legumin, increases considerably as germination proceeds> from 4.' 2 p.c. 

 in the resting seed to 55*5 p.c. of the total nitrogen, but rapidly 

 diminishes in the later stages. 



The nitrogen of the proteids insoluble in water, consisting chiefly 

 of the substance called by Eitthausen conglutin, diminishes at first 

 continuously during germination, but shows a marked increase when 

 the plant begins to take in nitrogen from the soil. This period is 

 characterised by the formation of new albuminoids, derived partly from 

 the transformation of nitrogen taken from the soil, but especially from 

 the conversion of the soluble amides into albuminoids. 



Changes in Nitrogenous Substances in Ripening of Cereals. § — 

 N. K. Nedokutschaeff has estimated the total nitrogen, and the nitrogen 

 in the form of proteids, asparagin and amides, in grains of rye, wheat, 

 barley, and oats, at different periods in the course of ripening of the 



* Tom. cit., pp. 539-64. 



t Ber. Deutsch. Chem. Ges., xxxiv. (1901) pp. 3811-4. See Journ. Chem. Soc. 

 lxxxii. (1902) i. p. 195. 



X Comptes Rendus, cxxxiv. (1902) pp. 995-8. 



§ Landw. Versuchs-Stat., lvi. (1902) pp. 303-10. See Journ. Chem. Soc, lxxxii. 

 (1902) ii. p. 281. 



