1916] AGRICULTURAL BOTANY. 333 



Experiments on the physiology of indigo-yielding' glucosids, F. R. Pab- 

 NELL i.]fem. Dept. Afjr. India, Bot. Ser., 7 {1915), No. 5, pp. 195-212). — Giving 

 details of a study on parts of several plants, the autlior states that an indigo- 

 j-ieldinjr jiliicosid is present in the roots and seeds of Wrightia tinctoria and of 

 W. tomentosa, but not in the leaves of the latter. The glucosid and its enzym 

 in ^V. tinctoria are distinct from those of Indigofera arrecta and /. sumatrana. 

 The glucosid content in W. tinctoria seed germinated and grown without 

 nitrogen supply increases to about 300 per cent in about 40 days, but it 

 decreases considerably as nitrogen starvation progresses. W. tomentosa seed- 

 lings show no appreciable increase of glucosid under like conditions. In cut- 

 tings of roJiigonum tinctorium and St7-obi1anthes flaccidifoVms grown without 

 nitrogen part of the glucosid disappears, presumably being used up as a nitroge- 

 nous reserve. In W. tinctoria and /. arrecta the maximum percentage content 

 occurs very early in the leaf development, the actual amount in any leaf 

 increasing during growth to maturity and then remaining constant until after 

 the leaves fall. 



Indican is produced in the dark by etiolated shoots of /. arrecta. There is 

 no variation in indican content between night and day in /. arrecta and /. suma- 

 trana, and no marked change is observable after keeping /. sumatrana in the 

 dark for 36 hours. 



No definite function is assigned to indigo-yielding glucosids in general or to 

 those of any particular species. 



Cytological observations on the raode of formation of anthocyanin pig- 

 ments in flowers, A. GriLLiERMOND {Compt. Rend. Acad. Sci. [Paris], 161 

 (1915), No. 17, pp. 494-49?).— Referring to the recent work of Moreau (E. S. R., 

 33, p. 523) as confirmatory of his own views previously noted (E. S. R., 30, 

 p. 729), the author gives a resume of the results of his own studies during 1914 

 and 1915. 



It is stated that in the flower of canna, the formation of anthocyanin involves 

 a process identical with that observed in leaflets of rose. Observations on 

 Pelargonium zonale and Iris germanica are also described. In the latter the 

 formation of anthocyanin presents two phases which are discussed. These 

 studies are held to confirm the conclusion previously reached by the author 

 and by Moreau that anthocyanin is formed in flowers exactly as it is in leaves. 



The coloring matters of chromatophores, H. Kylin {Naturiv. Wclinschr., 

 31 {1916), No. 7, pp. 97-103, figs. 8).— Noting results of studies on the color 

 constituents in higher plants and algae, the author discusses their properties 

 and their probable significance in connection with the activities of the plants. 



Alkaloid formation in plants. — I, Studies on protein and nicotin content 

 during growth, H. B. Rasmussen {Biochem. Ztschr., 69 {1915), No. 5-6, pp. 

 461-466). — These studies, carried out with Nicotiana rustica and with Hun- 

 garian and Virginia varieties of tobacco, show no clear and constant relation 

 between the richness of the fertilizers used and the nicotin content of the 

 resulting plants, but they do show an increase of nicotin with the age and 

 growth of the plants. The total nitrogen varied during growth according 

 to the variety of the plant and the situation of the leaves tested. In the less 

 strongly manured plants, the total protein nitrogen decreased with their age. 

 In the more heavily manured, the autumn content was greater than that of 

 August. 



The morning and evening content of mulberry leaves, L. Pigorini (Atti R. 

 Accad. Lincei, Rend. CI. Sci. Fis., Mat. e Nat., 5. ser., 23 {1914), II, No. 9, pp. 

 433-437). — Analyses of mulberry leaves are said to have shown that in sun- 

 light such leaves increase from morning to evening their content of organic 



