No. 3, April, 1921] PHYSIOLOGY 311 



no chlorophyll even when exposed to light, and will continue to grow thus on successive 

 transfers. When nitrogen is added to these chlorophylless growths the pigment is developed 

 and the algae become normal although kept in darkness. This property has been used by the 

 author in the attempt to determine whether bacteria introduced into the cultures of "white" 

 algae are capable of fixing free nitrogen. Positive results were obtained with mixed cul- 

 tures of a colorless alga and Azotobacter chroococcum. In the dark, when on acid malto- 

 gelatine, the alga in pure culture forms pigment, while on a neutral medium in the dark no 

 pigment formation takes place, although transfer to the light is followed by chlorophyll for- 

 mation. The addition of Azotobacter to "dark" cultures is also claimed to be followed by 

 chlorophyll formation. — A. Bonazzi. 



2143. Hepburx, Joseph Samuel, E. Quintard St. John, and Frank Morton Jones. 

 The absorption of nutrients and allied phenomena in the pitchers of the Sarraceniaceae. Jour. 

 Franklin Inst. 189: 147-184. 7 fig. 1920.— The general structure of the leaves of the various 

 species of the Sarraceniaceae, which are all found on the American continent, are described. 

 The nectar glands of the pitchers seem to exude d-fructose. The "wetting or narcotic prin- 

 ciple" in the pitcher liquor of some of the species does not seem to be a saponine. Active 

 proteolytic enzymes are present in all species of Sarracenia except S. psittacina, which was 

 not studied in this respect. Darlingtonia, a monotypic genus, seems not to have such an 

 enzyme. Closed pitchers are free from bacteria, but open ones soon contain proteolytic 

 bacteria. Milk, meat broth, and some other substances cause the secretion of additional 

 pitcher liquor. This liquid tends to return to its normal reaction to litmus in a few days 

 after acids or alkalies are introduced. Water is absorbed by the plant from the pitchers at a 

 slower rate than nitrogenous solutes and more rapidly than neutral phosphate in solution. 

 The pitcher liquor increases when a phosphate buffer with a nitrogenous substance in solu- 

 tion is introduced, and the nitrogen is absorbed. "The per cent of the introduced nitrogenous 

 compound or phosphate absorbed usually increased with the period of absorption." The 

 lithium ion was detected in the tissues of Sarracenia purpurea after neutral lithium citrate 

 had been introduced into the pitchers. Decrease in nitrogen and phosphorus was the cri- 

 terion used to determine the absorption of these elements from the pitcher liquor. — Ernest 

 Shaw Reynolds. 



2144. Strowd, W. H. The determination of nitrites and nitrates in plant tissue. Soil 

 Sci. 10: 333-342. 1920.— The Caron method and the nitron method of Busch as well as the 

 Kjeldahl-Gunning-Arnold method and the Kjeldahl method modified to include nitrates 

 are unsatisfactory for determining nitrates in plant tissue. The Devarda and Schloessing 

 methods with modifications can be used. The modifications are described. — W. J. Rabbins. 



2145. Strowd, W. H. The relation of nitrates to nodule production. Soil Sci. 10: 343- 

 356. 1920.— The concentration of nitrates in the cell sap of the roots of soy bean is many 

 times the concentration of nitrates in the soil. The concentration increases with arrested 

 photosynthesis and with increase in nitrate concentration in the soil, but not proportionately. 

 Nitrates have little effect upon the hydrogen-ion concentration of the plant juice. The 

 amount of reducing sugar in plants decreases with increase in nitrate. The concentration of 

 nitrate present in the plant sap when nodule production is inhibited is sufficient to prevent 

 the growth of Rhizobium leguminosarum in the soil. — W. J. Robbins. 



METABOLISM (ENZYMES, FERMENTATION) 



2146. Fernbach, A., et M. Schoen. Le role de I'aldehyde dans la fermentation alcoolique. 

 [The role of acetic aldehyde in alcoholic fermentation.] Bull. Inst. Pasteur 18 : 385-406. 1920.— 

 A review and a synthetic study of our knowledge on the subject. The work of Neubauer 

 and Fromhertz on the breakdown of the amino acids in the animal body by the path of 

 alanin-o-amino propionic acid-pyruvic acid-acetaldehyde-ethylic alcohol is taken as a start- 

 ing point for the review. The work of Neuberg and Karczag, Neuberg and associates, 

 Fernbach and Schoen, Maze, Lintner and Liebig, J. B. Dumas, Connstein, and Leudeke 



