316 " PHYSIOLOGY [BoT. Absts., Vol. VIII, 



the authors supporting the theory that vitamin A is formed in green tissues and not, in ap- 

 preciable quantities at least, in seed and other resting tissues. — A. R. Davis. 



2158. Delf, E. Marion. The distribution of accessory food factors (vitamines) in plants. 

 South African Jour. Sci. 17: 121-125. 1920. — The accessor}' food factors or vitamines are 

 widely distributed in the plant world and are associated with definite organs in the plant body. 

 Seeds possess the water soluble and anti-neuritic accessory factor, but less abundantly than 

 animal eggs. Green leaves possess both anti-scorbutic and fat-soluble vitamines in considera- 

 ble amounts; the etiolated leaves of the white "heart" of a cabbage possess anti-scorbutic 

 but no growth promoting qualities. Storage organs other than seeds contain chiefly the anti- 

 scorbutic accessory factor. Succulent fruits contain the anti-scorbutic vitamine even before 

 ripening is complete, and germinating seeds have considerable anti-scorbutic value even be- 

 fore the appearance of green leaves. Vitamines maj' thus be produced either in connection 

 with photosynthesis or in connection with the deposition of reserves. — E. M. Doidge. 



2159. Drummoxd, Jack Cecil, axd Katherixe Hope Coward. Researches on the 

 fat-soluble-accessory substance. V. The nutritive value of animal and vegetable oils and fats 

 considered in relation to their colour. Biochem. Jour. 14: 668-677. 1920. — The writers con- 

 clude that unless the existence of a leuco form is assumed, it does not appear probable that 

 the fat-soluble vitamine belongs to the lipochrome pigment group, and the frequently ob- 

 served association of the growth factor with such pigments must be regarded as accidental. 

 As a class, animal fats possess greater growth-activating power than vegetable oils; but ex- 

 ceptions exist, and no hard and fast line can be drawn. — A. R. Davis. 



2160. Drummond, Jack Cecil, and Katherixe Hope Coward. Researches on the 

 fat-soluble accessory factor (vitamin A). VI. Effect of heat and oxygen on the nutritive value 

 of butter. Biochem. Jour. 14: 734-739. Fig. 1-3. 1920. — The results obtained are in accord 

 with those reported by Hopkins (see Bot. Absts. 8, Entry 2191). — A. R. Davis. 



2161. Schertz, F. M. A chemical analysis of Sudan grass seed. Bot. Gaz. 69: 72-82. 

 1 fig. 1920. — This paper reports an analysis of unhulled dry seeds, seeds after germination, 

 and a microchemical analysis of the different parts of the seed. The results are given in tables, 

 and comparison is made with anajyses of other economic grasses. — H. C. Cowles. 



2162. Stephenson, Marjory. A note on the determination of the yellow plant pigments 

 from the fat-soluble vitamine. Biochem. Jour. 14: 715-720. 1920. 



2163. Wakeman, Nellie A. Pigments of flowering plants. Trans. Wisconsin Acad. 

 19: 767-912. 1919 [1920]. — The introductory chapter treats briefly of the theories of color 

 in organic compounds, approaching them from the general point of view of absorption spectra. 

 This is followed by an arrangement of the best known plant pigments according to a rational 

 scheme of classification, that is, according to the degree of saturation based upon the under- 

 lying hydrocarbon. Bj^ means of this arrangement certain relationships, not otherwise easily 

 observable, are emphasized, namely: (1) The influence of unsaturation in the molecule upon 

 the production of color, (2) the influence of so-called chromophorous groups, (3) the exist- 

 ence of homologous series of plant pigments, and (4) the existence of series of pigments re- 

 lated to similar symmetrical, or almost symmetrical, hydrocarbons of different degrees of 

 saturation. — Nellie A. Wakeman. 



2164. Willaman, J. J. Carbohydrate economy of cacti. [Rev. of: Spoehr, H. A. The 

 carbohydrate economy of the cacti. Carnegie Inst. Washington Publ. 287. 79 p. 1919 (see 

 Bot. Absts. 3, Entry 1744).] Bot. Gaz. 69: 91-92. 1920.— This contribution isregardedas 

 containing the most complete analysis of the carbohydrates of a single plant tissue that has 

 been obtained. — H. C. Couies. 



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