COLORING MATTERS. IO5 



masses, 1 and has been called diatomin (Nageli, 

 1849). ft i s easily removed from the thallus of the 

 Fucaceae by 40 per cent, alcohol, which does not 

 extract the chlorophyll. A small quantity of acid 

 colors it bluish-green. Alkalies, like light, 2 have 

 no pronounced influence on it. 



PHYCOPHAEIN (Millardet) 



Occurs in the thallus of Fucaceae, mixed with 

 chlorophyll and phycoxanthin. It is brown, soluble 

 in water but insoluble in alcohol. Further inves- 

 tigations, however, are necessary. 



B. Of the Cell Sap. 



(ANTHOXANTHIN. For a form of this, see 

 page 100). 



ANTHOCYANIN (Marquart; Kyanin, Fremy and Cloez) 



Is the blue coloring matter of many flowers. The 

 erythrophyll, which is peculiar to the cell-sap of 

 red and violet cells, is probably identical with this, 

 or only a modification of it. Acids impart a red 

 color to cells which contain anthocyanin, while 

 alkalies restore the blue color, the same as with 



1 Petit: De 1'Endochrome des Diatome'es. Bre"bissonia, 1880, Ann. 

 II., No. 7, p. 81. The composition of the endochrome was established in 

 1868 by Kraus and Millardet. 



2 Cf., however, Petit,/, c. 



