NOTES AND ABSTRACTS. 



163 



Phacelia, Oreocarya, Castilleja (2 sp.), Penisiemon, and Erigeron are 

 described in this paper. — G. F. S. E. 



New Plants from the Rocky Mountains. By Aven Nelson 

 {Bot. Gaz. July 1913, pp. 63-71). — Descriptions of new species of 

 Brodiaea, Eriogonum, Polygonum, Atriplex, Arcenthobium, Astragalus, 

 Chylisma, Azaleastrum, Gentiana, Mertensia, Oreocarya, Pentstemon, 

 Wyomingia, and Taraxacum. — G. F. S. E. 



Nitrate Decomposition in Soil Apart from Bacterial Action. 



By L Vogel {CentralbL /. Bakt., Bd. 34, Abt. 2, p. 540). — ^The author 

 makes the new and interesting observation that nitrates in the soil 

 may undergo decomposition quite apart from the action of denitrifying 

 bacteria. If sodium nitrate is distributed in thin layers of soil 

 containing 15 to 20 per cent, water, active decomposition of the 

 nitrate takes place, the nitrogen loss amounting to as much as 80 or 

 90 per cent. The decomposition of the nitrate occurred in various 

 different soils, free nitric acid being formed ; in the case of soils rich 

 in humus, nitrous acid was also produced, along with oxides of nitrogen. 

 The sodium combined with the calcium carbonate of the soil to form 

 sodium carbonate, leading to material alteration in the physical as 

 well as chemical characters of the soil. This non-bacterial decomposi- 

 tion of nitrate is probably related in some way to colloidal phenomena. 



F. C. 



Nitrates and Nitrites in Plant Tissues. By Richard Klein 

 (Beih. Bot. Cent. xxx. Abt. i, Heft i, pp. 141-166- 2 pL). — 

 The author describes various reactions for nitrates, and considers 

 " Nitron " (Merck's) is the best. Nitrates are especially common 

 in herbaceous plants and also in Tilia. (There is a list of plants in 

 which the author observed nitrates.) They are absorbed by the 

 root hair zone in the root, and also in the part below the root hairs, 

 but are not found in the root tips. Nitrates are especially common 

 in the pith and cortical parenchyma, in the leaves generally near the 

 vascular bundles, but are seldom found in the flowers. They occur 

 chiefly in unripe fruits, probably showing that they are assimilated 

 in the fruit to which the nitrogen is carried in inorganic form. They 

 occur in the sap of seedlings, but apparently not in that from the 

 regular nitrate plants. For nitrites the author used Griess' reaction. 

 They do not occur in the sap drawn from cut stems of Fuchsia, but 

 are formed in it by bacteria and fungi. Nitrites were found in the 

 sap of etiolated Potato shoots when these developed without access 

 to salts in solution, also in tubers before germination, in the sap of 

 Erythrina leaves, and in the root tubercles of Leguminosae, but they 

 do not occur in Sagittaria or Pisum. The reaction in the last two 

 cases is due to anthocyan.— G. F. S. E. 



Nitrification in Different Soils. By H. Fischer {Landwirtsch. 

 Jahrb., Bd. 41, p. 755). — ^The author found that nitrification takes 

 place more rapidly in a somewhat heavy soil than in a light sand. 



M 2 



