AGRICULTURAL BOTANY. 27 



So far as their exiierinieiits go, the authors chxim that there is no reason to 

 doubt the general distribution of such an enzym in green plants. In the normal 

 plant the only conditions necessary for nitrate reduction seem lo be the presence 

 of the enzym found in roots, stems, and leaves, and a suitable carbohydrate. 

 The latter condition suggests the green leaf as the center of reduction, and 

 this agri'es with the distribution of nitrates in the ])lant. 



The role played by proteins and the decoinposition products of albumi- 

 noids in fermentation, Ehklich {Amcr. Brewer, ^1 (190S), Xos. J, pp. JO, 1 1 ; 

 2. pi>. ()l-()'i). — This is a paper, read by the author before a brewing associa- 

 tion at a meeting in Berlin, in which he describes the role played by albumi- 

 noids in the process of fermentation. He calls attention to a newly discovered 

 property of proteids in their I)ehavi()r during fermentation and to a new reac- 

 tion of yeast cells. This subject is at present believed to be of theoretical 

 interest only, but will undoubtedly prove of considerable ai»plicntion. 



*' Up to the present time it has been generally accepted that only carbohy- 

 drates, maltose, etc., are capable of undergoing alcoholic fermentation through 

 the agency of the yeast. It has now been found, however, that in every fermen- 

 tation of sugar by living yeast cells the albuminoids in their last stage of 

 decomposition — i. e., in the form of amino acids — suffer decomposition, inas- 

 much as they are decomposed not only into carbonic acid and others, but also 

 mainly into alcohol, besides some aldehyde and acids of various form, so that 

 we may now justly speak of an alcoholic fermentation of albumen. This 

 hitherto unknown protein fermentation is not limited to the nitrogenous sub- 

 stances of the wort, but extends to the yeast albumen also: it is brought about 

 by a peculiar breaking down and building ui» of the albumen of the living cell 

 and leads to the formation of a number of nonnitrogenous substances. Up to 

 the present these substances had erroneously been regarded as by-i)roducts of 

 the fermentation of sugar." 



A study of the role and function of mineral salts in the life of the plant, 

 N. T. Deleano (Inst. Bot. Univ. Gendve [Pub.], 7. ser., 1907, No. fi, pp. //N; abs. 

 in Bot. Centbl.. 107 (1908), No. 1, p. //) .—According to the author, there is a 

 double movement of mineral material during the life of the plant, one from the 

 soil to the plant and the other from the plant to the soil. These movements 

 are termed by him positive and negative migrations. Concerning the latter 

 there appears to be but little information, and it is with this that the author 

 has carried on investigations. 



He found under certain conditions that plants could return to the soil min- 

 eral matter equal to 50 per cent of the plant's weight. While the nitrogen 

 content of the plant remains fairly constant after once attaining a maximum, 

 and the carbohydrates increase and are stored up, the mineral matter gradually 

 diminishes until the death of the plant. The cause of this negative migration 

 is said to be due to the fact that the mineral matter is not truly assimilated 

 by the i)lant but is held by the plasma of the cells through its semipermeability. 

 When the vitality of the cell becomes reduced or the cells are dead the plasma 

 ))ecomes permeable and the mineral matter escapes by simple diffusion. 



The experiments upon which the author's conclusions were based were con- 

 ducted with oats fertilized in various ways. He found with these plants that 

 the water content began to diminish after the forty-third day and at the same 

 time the mineral matter began to decrease. In this way the composition of the 

 plant .iuices remained practically constant. 



The possible role of lig-ht in relation to alpine plants, C. H. Shaw (Abs. 

 in Scicnrr, n. ser., 21 (190S), No. (J87, p. .139). — The author reports that readings 

 of the actinometer and the black bulb thermometer in vacuo in the region alxmt 

 the Selkirk Mountains seem to prove that light at high altitudes is iMtnsiderably 



