826 EXPERIMENT STATION RECORD. 



On the formation of hydrocyanic acid in plants, A. Joeissen {Acad. Roy. 

 Belff., Bui. CI. Sci., No. 3 (1914), pp. 130-131; abs. in Nature [London], 94 

 {1914), ^^0. 2340, p. 7). — ^Attention is called to the fact that citric acid in the 

 presence of oxidizing agents and a trace of nitrate gives rise to hydrocyanic 

 acid, and that in dilute solution in sunlight small quantities of ferrous or ferric 

 salts can bring about the preliminary oxidation of the citric acid. As citric 

 acid is widely distributed in plants, the author considers that hydrocyanic 

 acid may possibly be produced in them through the action of sunlight on citric 

 acid in the presence of traces of iron salts. 



The oxidases of acid tissues, G. B. Reed {Bot. Gaz., 57 {1914), No. 6, pp. 

 528-530). — Results of work done by the author are said to suggest that the 

 apparent absence of oxidases in some oi'ganisms as reported by some authors 

 may be due to faulty methods of observation. Having obtained results com- 

 parable with those reported by Clark (E. S. R.. 30, p. 203), who noted a relation 

 between apparent absence of oxidases and acid reaction, the author made special 

 tests with citrus fruits, from which it appeared that these have normal oxidases 

 in their acid tissues, also that these oxidases are protected in some manner from 

 the action of the acid, which at the usual concentration inhibits the action of 

 the oxidases. 



The author thinks this protection may be afforded by a semipermeable sur- 

 face (plasma membrane or cell walls similar to the cell walls of barley seed), 

 through which the acid is imable to pass. When the tissue is ground, pre- 

 vious to expressing the juice, the structure which separates the acid from the 

 ferment is destroyed so that the action of the latter is inhibited. It is thought 

 probable that this condition is a general one in acid tissues. The general 

 effects of acids and alkalis on oxidase ferments are now under investigation. 



Some accessory factors in plant growth and nutrition, W. B. Bottomley 

 (Proc. Roy. 80c. [London], Set: B, 88 {1914), No. B 602, pp. 237-247, figs. 2).— 

 Experiments are reported in which the manurial value of sphagnum peat which 

 had been incubated with a mixed culture of aerobic soil organisms was tested. 

 The results obtained indicated that the growth-stimulating action of the bac- 

 terized peat might be due to the presence of a substance or substances similar 

 in nature to the accessory food bodies concerned in animal nutrition. 



In another series of experiments extracts of bacterized peat were tested on 

 the growth and fixation of nitrogen by Azotobacter chroococcum, and the re- 

 sults obtained indicated that there is present a substance which stimulates 

 plant growth, and that it is of a fairly stable nature. Further investigations 

 showed that this active stimulant could not be obtained directly from raw peat, 

 but was evidently the result of bacterial action. 



In another series of experiments a solution was tested on wheat seedlings 

 deprived of their endosperms, but furnished with a nutrient solution and the 

 same solution containing the extract from peat. After 17 days the weights of 

 the plants were obtained, showing a decided increase where the bacterized peat 

 solution has been employed. 



Bioreactions of tellurium and their applicability to the study of vegetable 

 physiology and pathology, G. Pollacci {Aiti 1st. Bot. R. Univ. Pavia, 2. sen, 

 15 {1914). PP- 281-284, fig. i).— This is a brief report on the effects produced 

 by tellurium on plants and their parasites, as shown by experiments with roots 

 of Brassica attacked by Plasmodiophora hrassicw. The effects produced when 

 these were kept 48 hours in a solution containing a very small proportion of a 

 tellurium salt indicate that this fungus Is able to reduce the salt. 



The effect of the soot in smoke on vegetation, J. F. Clevengee {Mellon 

 Inst. Indus. Research, Smoke Invest. Bui. 7 {1913). pp. 26, pis. 8, figs. 2).— The 

 results are given of an investigation to determine the effect of soot in smoke 



