226 EXPERIMENT STATION RECORD. [Vol.35 



In acidity related to its extent. Tlie acid content does not vary greatly with 

 age, except in very young tissue. The actual rate of carbon dioxid production 

 is greatest in the youngest tissues, next in the old turgid joints, and least in 

 the flaccid joints, the gas interchange ratios varying according to the acidity 

 conditions rather than according to the age of the tissue. In general, high 

 acidities, high evolution rate of carbon dioxid, and high carbon dioxid-oxygen 

 ratios are associated. No difference of acidity was found between the base and 

 tlie tip of the joint, but most of the acid was held in the layers of soft, highly 

 turgid cells outside the bundle ring. Some discussion of the bearings and im- 

 plications of the facts as observed is also given. 



Localization of acids and sugars in fleshy fruits, E. Demoussy (Compt. 

 Rend. Acad. Sci. [Paris-i, 161 {1915), No. 15, pp. ^43-445).— Tabulated results 

 of analyses of the juices obtained from a number of fleshy fruits by employment 

 of gi-aduated pressures show that the increase of acidity and reducing sugars 

 due to pressure, while considerable in case of a few fruits, was slight, lacking, 

 or negative in others, so that a positive increase can not be considered as 

 general. The variations due to pressure in case of nonreducing sugars were 

 usually opposite in direction to those in acidity and in reducing sugars. The 

 chemical composition of a fruit varies in different fruits in portions apparently 

 homogeneous otherwise and in spite of the fact that they may have the same 

 proportion of water, which appears to circulate more readily than do certain 

 solutes. 



These studies are considered to have brought out striking conformities to 

 the law announced by Maquenne (E. S. R., 8, p. 844), according to which 

 soluble bodies tend to accumulate at points in the living organism where there 

 is a lowering of the osmotic pressure. This law is used to explain such 

 phenomena as the accumulation of acid in certain portions of fruits during the 

 process of cooking. 



What are chondriosomesP D. M. Mottieb (Abs. in Science, n. ser., 43 (1916), 

 No. 1104, pp. 286, 287). — In addition to the choudriosomes occurring in higher 

 plants, which become leucoplasts in case they occur in the roots and chloroplasts 

 when in the stems, the author calls attention to the presence in cells of certain 

 plants of other bodies similar in structure and reaction which do not develop 

 into either leucoplasts or chloroplasts. These bodies are said to be ahvays pres- 

 ent in the form of granules or delicate rods, and, as they are permanent organs, 

 they should be given morphological rank. They do not arise from the nucleus, 

 and the question is raised as to whether the term chondriosome should be 

 applied to the organs under discussion. 



Rapid methods for quantitative and qualitative studies on the soil flora, 

 T. F. Manns (Abs. in Science, n. ser., 43 (1916), No. II04, p. 288).— For the 

 rapid study of soil organisms, the author suggests the use of a mechanicl shaker, 

 in conjunction with suitable media. It is claimed that where the shaker was 

 used it was possible to plate 16 soils in duplicate plates with 2 dilutions on 

 four different media in from 2J to 3 hours. Usually three media will suffice to 

 bring out the important groups, one for the ammonifying organisms and the 

 saprophytic forms, including molds, etc., a second for Bacillus radicieola, and a 

 third for Azotobacter, B. radiobacter, and nitrifiers. 



Media for quantitative and qualitative studies on Azotobacter and nitri- 

 fiers, T. F. Manns (Abs. in Science, n. ser., 43 {1916), No. IIO4, pp. 288, 289). — 

 In making a survey of the bacteria in various groups of soil organisms, the 

 author found that a soil extract agar, to which was added 0.5 gm. of a mixture 

 of insoluble salts, would bring out the nitrogen-fixing organisms and the nitri- 

 fying organisms. 



