38 Physiologie. 



controlled by the biological, physical, and chemical conditions 

 prevailing in the soll at any given time. s. H. Vines. 



ScHUNCK, C. A., The Yellow Colon ring Matters 

 accompanying Chlorophyll, and their Spectro- 

 scopic Relation s. Part. II. (Proceedings Royal Society. 

 Vol. LXVIII. 1901. p. 474.) 



In a previous paper (Proc. Roy. Soc. Vol. LXV. p. 177. 

 1899) the author had come to the conclusion that all crude 

 alcoholic extracts of healthy green leaves contain two yellow 

 colouring matters: the one, chrysophyll, deposits from the 

 extracts in lustrous red crystals; the other, xanthophyll, is 

 obtained by treating the extracts with animal charcoal in the 

 cold, when the charcoal takes up the Chlorophyll and leaves 

 a yellow Solution which deposits xanthophyll as an amorphous 

 substance. 



In the present paper, the author gives an account of his 

 investigation of the crude yellow Solution. It became evident 

 that more than one yellow colouring matter was present in it, 

 and the attempt was made to isolate these substances by means 

 of CS2 (Sorby's method). Most of the experiments were 

 made with alcoholic extracts of the leaves of Flciis Carica and 

 Ficus repens: the observations of the absorption-spectra were 

 made by photography. 



The crude yellow alcoholic Solution generally shows four 

 absorption bands in the violet and ultra-violet between the 

 lines F and L. By agitating the alcoholic Solution with 

 successive quantities, each about half its volume, of CSi, until 

 no more colouring matter was taken up by the CSü, a series 

 of fractionated Solutions in CSa were obtained, which were 

 evaporated to dryness and the residues redissolved in alcohoL 

 On examining these Solutions spectroscopically a series of 

 spectra was obtained from which the author concludes that the 

 crude yellow alcoholic Solution is a mixture of chrysophyll and 

 the colouring matter or matters remaining in the alcohol after 

 fractionation, together with the colouring matter formed from 

 the latter by the action of the acid present: and that therefore 

 he was wrong in concluding that the four-banded spectrum of 

 the crude Solution represented a Single colouring matter to 

 which he restricted the name xanthophyll. He considers that 

 chrysophyll preexists in the leaf, and is not formed from an other 

 colouring matter: he thinks that it corresponds to the orange 

 xanthophyll of Sorby. There is some reason to believe that 

 chrysophyll is realy identical with Carotin, but the author does' 

 not allude to this possibility. S. H. Vines. 



Dandeno-JAMES, B., The Application of Normal Solu- 

 tions to Biological Problems. (Botanical Gazette. 

 XXXII. 1901. p. 229.) 



