718 EXPERIMENT STATION RECORD. 



Soc. [London], 98 {1910), No. 577, II, p. 987). — It was found that potassium, 

 calcium, magnesium, phosphorus, and sulphur were all essential to the develop- 

 ment of Azotobacter. A deficiency in any of these mineral elements of the 

 nutritive solution resulted in a less economical utilization of the dextrose and 

 a consequent decrease in the amount of nitrogen flxed per gram of dextrose. 

 The addition of potassium, sodium, and magnesium compounds above certain 

 limits was found to act injuriously on the Azotobacter. 



The influence of the culture media on the formation of diastase by molds, 

 K. Saito (Wchiischr. Brau., 27 (1910), No. 16, pp. 181-183; abs. in Bot. Centbl, 

 llJf (1910), No. 2Ji, pp. 618, 619). — The results are given of experiments on the 

 formation of diastase by Aspergillus oryzw when grown on different nutritive 

 media. 



It was found that the source of the nitrogen supply had great influence on 

 the amount of diastase formed. Nutritive media with organic nitrogen com- 

 pounds, such as peptone, tyrosin, leucin, etc., gave good results, but this was 

 not the case when inorganic acids, such as ammonium chlorid, ammonium 

 sulphate, ammonium nitrate, etc., were used. The source of the carbon supply 

 had no appreciable influence on the formation of the diastase by the mold. 



The translocation of carbohydrates in plants, S. Mangham (Scl. Pi-og. 

 Twentieth Cent., 5 (1910), No. 18, pp. 256-285, figs. 16; 5 (1911), No. 19, pp. 

 Ji57-Ji79, figs. 3). — The author gives a summary of literature relative to the 

 path of the translocation current and describes his experiments on the trans- 

 location of sugars. 



From a histological and anatomical study he concludes that sugars pass from 

 the chlorophyll tissues of the leaf into the bundle sheaths of the finer veins 

 and are thence removed by the sieve tubes. Physiological experiments seem 

 to confirm this conclusion. 



The author reports that the use of Fehling's solution in his investigations 

 was unsatisfactory as a test, and he recommends the method introduced by 

 Senft, by which osazones of the sugars are formed. These are said to be 

 easily seen and are permanent in glycerin. The sieve tubes were frequently 

 conspicuous on account of the bright yellow osazones when none were to be 

 found in the surrounding parenchyma. 



Work is in progress with some of the lower plants to determine how far the 

 sieve tubes serve to conduct carbohydrates. 



A bibliography on the translocation of carbohydrates is appended. 



Role of reduction processes in the respiration of plants, W. Zaleski (Ber. 

 Dent. Bot. GeselL, 28 (1910), No. 7, tip. 319-329; ahs. in Jour. Chem. Sac. 

 [Londoni, 98 (1910), No. 577, II, p. 990 ) .—According to investigations of the 

 author the reducing power of various seeds, as indicated by methylene blue, 

 was found to be greatest in peas and least in cereals and oil-bearing seeds, while 

 wheat and lupines occupied an intermediate position. There is claimed to be 

 a certain parallelism between the anaerobiose and the reducing power of seeds, 

 since anaerobiose is highest in leguminous seeds and lowest in cereal and oil 

 seeds. 



Acid salts were found to depress the reducing power of peas. Neutral salts 

 and sodium selenite acted still more unfavorably, while alkalis, especially the 

 dibasic phosphates, stimulated the reduction process. 



The relation between chlorophyll and photosynthetic energy, W. N. Lubi- 

 MENKO (Trudy Imp. 8. Petert). Ohslich. Estcstvo. (Trav. 8oc. Imp. Nat. St. 

 Peters}).), U (1910), III, No. 1-2, pp. 266, figs. 9).— The author has sought to 

 establish the rehitiou between the amount of chlorophyll and the photosynthetic 

 energy of plants. 



