310 PHYSIOLOGY [BoT. Absts., Vol. VII, 



Versuchssta. 93: 135-146. 1919. — Beans and lupines were grown on a loamy sand soil without 

 lime and with 1, 5, and 10 per cent additions of ground limestone. Harmful effects in propor- 

 tion to the amount of liming were shown during the earlier stages of growth by yellowing of 

 the leaves and even dying of the lower leaves in the worst cases, but these apparently harm- 

 ful effects disappeared as the plants grew older. The hydrogen-ion concentrations of the 

 juices of the roots and tops were determined at the time of blossoming and were found to be 

 the same regardless of the amount of liming. The conclusion is that though plants grown on 

 limed soil probably take up more lime, they are able to maintain the same acidity relations 

 in their juices as on unlimed soil. It is pointed out that these determinations were made 

 only at the time of blossoming and that there might be differences in the acidity of the plant 

 juices at other stages of development. — A. T. Wiancko. 



2139. Ltjigi, Bernardini. La nicotina nel tabacco (contributo alio studio della genesi e 

 della funzione degli alcaloidi.) [Nicotine in tobacco (contribution to the study of the genesis 

 and function of the alkaloids).] Atti R. Accad. Lincei Roma Rend. (CI. Sci. Fis. Mat. e Nat.) 

 V, 29^ : 62-66. 1920.— The amount of nicotine in different parts of tobacco plants at differ- 

 ent ages was determined. Analysis of very young plants with minute first leaves showed 

 nicotine when grown in light but not when grown in darkness. Plants severely pruned did 

 not utilize the nicotine as reserve nitrogen, and germinating tobacco seeds were retarded in 

 germination by very dilute solutions. — F. M. Blodgett. 



2140. PoNSELLE, A. Determination de la reaction des milieux de culture par la mesure 

 de la concentration en ions hydrogene. [Determination of the hydrogen-ion concentration of 

 culture media.] Bull. Inst. Pasteur 18: 601-610. 1920. — This is a short review of the theory 

 of acidity and of the principles underlying the methods for the determination of hydrogen-ion 

 concentrations. A few examples of simple calculations to be used in determining Ph values 

 and a short exposition of the technique of the colorimetric methods are given. The work of 

 ScRENSEN, HoRWiTZ, Meyer and OsTENBERG, Clark and LxTBS, Homer, Ponselle, Bar- 

 NETT and Chapman, and of Fennel and Fisher is reviewed. The reader is cautioned against 

 the use of the colorimetric method in adjusting the reaction of deeply colored media, and 

 reference is made in this connection to the electrometric methods. The contribution is in 

 fact a guide to be used in daily bacteriological operations and not a theoretical discussion 

 of the subject. — A. Bonazzi. 



2141. Ravenna, C, e G. Bosinelli. Sul dipeptide dell'acido aspartico e suUa funzione 

 dell'asparagina nelle piante. [Upon the aspartic acid dipeptide and the function of asparagine 

 in the plant.] Gazz. Chim. Ital. 50: 281-288. 1920.— ^This is a continuation of the inves- 

 tigations published in 1919. The authors find that after long boiling, solutions of asparagine 

 gave the biuret reaction, and were precipitated by lead acetate. The precipitate filtered and 

 deleaded with H2S gave a white amorphous powder of the following elementary composition: 

 C, 38.78; H, 4.85; N, 11.60. Aspartic acid on the other hand yielded only ammonium aspar- 

 tate. The authors conclude that the acid amides and not the simple amino acids are directly 

 concerned in the building of polypeptides and the subsequent protein synthesis in plants. 

 As PiUTTi claims asparagine to be a /3-asparagine the polypeptide obtained must be formed 

 by the linking of the amidic group on one side with the carboxylic on the other and should be 

 isomeric with the /3-polypeptide obtained by Fischer and Koenigs from 2-5 diketopipera- 

 zin-3-6 diacetic acid. — -A. Bonazzi. 



METABOLISM (NITROGEN RELATIONS) 



2142. Cauda, A. Metodo pratico per svelare negli schizomiceti I'attitudine a fissare 

 I'azoto libero. (Nota preliminare.) [A practical method for the detection of nitrogen fixing 

 properties in bacteria. A preliminary note.] Staz. Sper. Agrarie Ital. 53: 79-80. 1920. — The 

 growth of unicellular algae, such as Chlorella vulgaris, Prolococcus, and Chlorococcus, upon 

 calcium carbonate-malto-gelatine is distinctly variable and directly correlated with nitrogen 

 content of the medium. On agar to which no nitrogen has been added these algae develop 



