502 Varietäten etc. — Physiologie. 



One of these is the flavone apigenin (C15H10O5) present in the 

 „ivory" variety and the other is the flavone luteolin (CisHioOg) pre- 

 sent, in addition to apigenin, in yellow varieties. Genetically, the 

 ivory variety is dominant to the yellow and contains a factor „I" 

 absent from the yellow which may be expressed as the „power to 

 inhibit the formation of luteolin". The albino variety does not con- 

 tain apigenin or luteolin. 



The remaining colour varieties contain, in addition to flavones, 

 anthocyanin of which there are two kinds only: 



1) Red anthocyanin — giving a) yellow tinged with bronze or 

 bronze (according to the amount present) when present together 

 with luteolin and b) Ivory tinged with rose-dore or rose dore when 

 present together with apigenin. 



2) Magenta anthocyanin — giving a) yellow tinged with crim- 

 son or crimson when present with luteolin and b) Ivory tinged with 

 magenta or magenta when present with apigenin. The authors 

 describe in detail the methods they employed for the preparation 

 and purification of these two anthocyanin. 



The pure pigments were obtained as powders — Indian red 

 and magenta red respectively — readilj'- soluble in absolute alcohol 

 and Pyridine, slightly soluble in dilute acids, ethyl acetate and 

 acetone, almost insoluble in water and insoluble in ether, Chloro- 

 form and benzene. Both formed insoluble coloured lead salts and 

 gave characteristic colour reactions with concentrated sulphuric 

 acid and with ferric chloride. 



In neither case has the anthocyanin been obtained in crystal- 

 line form. In spite of this however, the constancy of the combustion 

 results obtained from material derived from different sources, to- 

 gether with the failure to effect any Separation even though many 

 solvents were employed, satisfy the authors that their pigments are 

 Single substances. 



The combustion results indicate as the simplest formulae 

 CgHgOj for the red and Cj^HigOio for the magenta. Boiling point 

 determinations of the molecular weight would appear to indicate 

 that the molecule is Co^HoyOis for red (M. W. = 555) and CgoHggOao 

 for magenta (M. W. ="716). 



The authors refer to Willstätters very different conclusions 

 regarding Cornflower pigments and conclude that the anthocyanins 

 of the two genera differ considerably from each other. 



They further consider that the anthocyanins of Antirrhinuni , if 

 flavone derivatives, are more complex than flavones and may be 

 formed by condensation accompanied by oxidation or possibly con- 

 densation with phenols &c. W. Neilson Jones. 



Zsak, Z., Nehäny erdekes hybrid Budapest flöräjäban. 

 [Einige interessante Hybriden in der Flora von Buda- 

 pest]. (Mag. bot. lapok. XV! 1/5. p. 60—61. 1916.) 



In der Umgebung von Budapest fand Verf. folgende Hybri- 

 den: Jitncns Roeperi A. et G. [fuscoater X lampocarpus), Euphorbia 

 angustifrons Borb. {pannonica X Gerardiana), Carduus Haslinsskya- 

 nus Budai {collinus X nutans), Carduus Soltessii (acanthoides X (^ol- 

 linus). Matouschek (Wien). 



Dixon, H. H. and W. R. G. Atkins. Osmotic Pressure in 

 Plauts. VI. On the Composition of the Sap in the Con- 



