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



1465. Lapicdue, Louis. Variation saisonnidre dans la composition chimique des algues 

 marines. [Seasonal variation in the chemical composition of marine algae.] Compt. Rend. 

 Acad. Sci. Paris 169: 1426-1428. 1919. — Laminaria flexicaulis was selected as typical material 

 for this work. Analysis of the carbohydrate content and of the soluble and insoluble ash 

 showed that there is a distinct seasonal variation in the chemical composition of this alga. 

 From the spring equinox until September there is a steady increase in soluble carbohydrates 

 from 1.1 to 33.9 per cent. At the same time there is a decrease in the soluble ash from 28.2 

 to 13.4 per cent and of the insoluble ash from 7.5 to 4.6 per cent. Soluble carbohydrates in- 

 creased from the end of winter to smnmer in the ratio of 2 to 81. The carbohydrates present 

 are mannite [included for convenience in this group] and laminarine. The author suggests 

 that the disappearance of soluble ash with the increase in soluble carbohydrates may be 

 simply an "isotonic substitution." — V. H. Young. 



1466. MoBius, M. tJber die Farben der Blumen. [On the colors of flowers.] Ber. Sen- 

 kenberg. Naturf. Ges. Frankfurt, a. M. 49: 108-109. 1919. — In this report of a lecture given 

 in February, 1919, the biological significance of colors in flowers is stated to be an unsolved 

 problem, if insects are color-blind. In producing the various color-effects the following 

 pigments are the only ones involved: Chlorophyll, anthoxanthin, anthocyan, anthochlor, and 

 anthophaein. These occur, however, in many different arrangements. — A. W. Evans. 



1467. MoYCHO, Venceslas. Recherches sur le role physiologique de la saponine. [In- 

 vestigations concerning the physiological role of saponin.] Rev. Gen. Bot. 32 : 449^59. 1920. 

 —Investigations were made of the amount of saponin present at different stages of the devel- 

 opment of Saponaria officinalis. It was found that the relative amount of saponin present 

 was approximately constant until the time of flowering and seed production, when the amounts 

 present decreased. The glucoside was again accumulated in the roots in the autumn and 

 winter after the foliage had died. The author concludes that the glucoside may be utilized 

 by the reproductive organs of the plant. The accumulation does not depend on the emigra- 

 tion of the glucoside from the leaves but is due to its formation in the storage organs of the 

 plant. — /. C. Gilman. 



1468. Tanuet, Georges. Sur la miellee du peuplier. [On the honey dew of poplar.] 

 Compt. Rend. Acad. Sci. Paris 169: 873-874. 1919.— The "honey dew" which collects on the 

 leaves of Populus nigra was collected from 6 kilos of leaves and analyzed by appropriate 

 methods to determine its carbohydrate content. Twenty-two grams of "melezitose" were 

 secured from this amount of leaves. "Honey dew" of poplars appears to be formed by the 

 excretion of minute droplets by plant lice. — V. H. Young. 



14G9. Witzemann, E. J. Disodium phosphate as a catalyst for the quantitative oxidation 

 of glucose to carbon dioxide with hydrogen peroxide. Jour. Biol. Chem. 45: 1-22. 1921. — 

 Glucose may be quantitatively oxidized to CO2 with hydrogen peroxide in the presence of a 

 phosphate mixture. Disodium phosphate plays the role of a typical catalyst in the oxida- 

 tion. — G. B. Rigg. 



METABOLISM (NITROGEN RELATIONS) 



1470. Dakin, H. D. Amino acids of gelatin. Jour. Biol. Chem. 44:499-529. Fig. 1. 

 1920. — The products of the hydrolysis of gelatin were found to contain 13 amino acids. The 

 ones present in largest amounts were glycine, hydroxyproline, proline, alanine, and arginine. 

 — G. B. Rigg. 



1471. Johns, C. O., and C. E. F. Gersdorfp. The globulin of the cohune nut, Attalea 

 cohune. Jour. Biol. Chem. 45: 57-67. 1921.— Cohune nut globulin contains all of the basic 

 amino acids known to exist in proteins, being high in arginine and lysine. — G. B. Rigg. 



1472. Johns, C. O., and D. B. Jones. Some amino-acids from the globulin of the coco- 

 nut as determined by the butyl alcohol extraction method of Dakin. Jour. Biol. Chem. 44: 



