90 PHYSIOLOGY [BoT. Absts., Vol. VIII, 



626. Beidel, M. Sur la presence simultanee du gentianose et du saccharose dans les 

 especes du genre Gentiana. [The presence of both gentianose and saccharose in gentian.] 

 Jour. Pharm. et Chimie 21: 306-311. 1920. — The simultaneous presence of both gentianose 

 and saccharose in Gentiana lutea, G. asclepiades, G. punctata, G. cruciata, and G. purpurea can 

 be explained by the gentiobiase (the ferment in gentian) acting both hydrolytically and 

 synthetically, forming from the gentiobiose first saccharose and then, during the subsequent 

 development of the root, transforming this again into gentiobiose. — H. Engelhardt. 



627. Last, E. tjber die quantitative Bestimmung von geringen Zuckermengen bei Gegen-!- 

 wart von hoheren und niederen Eiweissabbauprodukten. [The quantitative determination of 

 small amounts of sugar in the presence of complex and of simple decomposition products of 

 proteins.] Biochem. Zeitschr. 93: 66-81. 1919. — The Bertrand titration method was used 

 and the following abstract of his conclusions exhibits his results as to the limitations of the 

 method. Precipitation of protein decomposition products affecting quantitative sugar 

 determination is effected by using 2 g. neutral HgCl2 per g. of protein (albumose, peptone) 

 present. Acid and excess of HgClz are to be avoided. Precipitation with Hg(N03)2 accord- 

 ing to the Patein-Dufau method is satisfactory when accurately done. — If ereptone is pres- 

 ent, there is a factor of error ascribed to the atomic grouping in the molecule. This is due 

 to solution of cuprous oxide by the ammonia set free, and occurs either with boiling in alkaline 

 solution or on long standing. Neutral HgCla also precipitates ereptone in the test solutions 

 to a degree sufficiently complete to give accurate sugar values. Here also precipitation with 

 Hg(N03)2 is satisfactory. — W. W. Bonus. 



628. Ltjmiere, Auguste. Les vitamines sont-elles necessaires au developpement des 

 vegetaux? [Are vitamines necessary to the development of plants?] Compt. Rend. Acad. Sci. 

 Paris 171 : 271-273. 1920. — Fungi were cultivated on purely mineral and organic nutrients 

 without the addition of vitamines and developed equally as well as in the presence of vita- 

 mines. Experiments are referred to which attempt to determine the properties of vitamines, 

 such as precipitation, filtration, etc. — C. H. Farr. 



629. RiCHTER-QtJiTTNEE, M. Eine Mikromethode der Acetonbestimmung. [A micro- 

 method of acetone determination.] Biochem. Zeitschr. 93: 163-171. Fig. 1-2. 1919. 



630. Sherrard, L. C, and G. W. Blanco. The acid hydrolysis of sugar cane fiber and 

 cotton seed hulls. Jour. Indust. Eng. Chem. 12: 1160-1162. 1920.— Of the total sugars pro- 

 duced by the acid hydrolysis of these materials, only a small quantity is fermentable, the 

 larger portion being of the pentose variety.--— jFfenry Schmitz. 



631. TUNMANN, O. tJber die Alkaloide bei Verwundungen der Pflanzen. [Alkaloids in 

 relation to wounding of plants.] Biochem. Zeitschr. 95:164-169. 1919.— The author has 

 checked the work of Troegele, using Atropa Belladonna and Pilocarpus pinnatifolius . His 

 conclusions, based upon quantitative and microchemical data obtained from these plants 

 when subjected to traumatisms and to snail depredations, are that such injuries do not result 

 in increased alkaloidal content. — W. W. Bonns. 



632. Wissell, von. Ueber die chemische Bestimmung der Starke in verschiedenenReisig- 

 arten und einigen anderen Pflanzenstoffen. [The chemical determination of starch in various 

 kinds of prunings and other plant materials.] Landw. Jahrb. 53 : 618-625. 1919. — The author 

 describes in detail 2 methods for determining chemically the quantity of starch in plant 

 materials and concludes that the method of Ewers, involving extraction with hot weak hydro- 

 chloric acid without pressure, gives more dependable results than that of Reinke involving 

 the use of high pressures. — A. J. Pieters. 



633. Zijp, C. VAN. Over de mogelijkheid van het ontstaan van Hexamethyleentetramine 

 in assimileerende planten end eene microchemische reactie op ammoniumzouten. [The possi- 

 bility of the production of hexamethylenetetramine in assimilating plants and a microchemical 



