CAROTINOIDS IN THE PHANEROGAMS 87 



Montcvcrde and Lubimcnko (1913b) this pigment is rhodoxunthin, the 

 red isomcr of xanthophyll. True carotinoids are not present in the 

 aril of Myrixtica fnujrans Houtt. (Nutmeg), judging from Kohl's 

 (1902) classification of the pigment as a xanthophyll showing no 

 jqurtroscopic absorption properties. Lubimcnko (1914a), however, 

 reports lycopin in the aril of this plant. 



Other seeds which are not characterized by highly pigmentcd endo- 

 carpellary tissue have been found to contain carotinoids although 

 nothing is known regarding the distribution of the individual caro- 

 tinoids among the total pigment. These seeds are characterized by 

 yielding a yellow oil on pressure. Gill (1918) has tested by a carotin- 

 oid color test flax seed (Linium usitatissimum, the linseed of com- 

 merce), mustard seed (Brassica nigra) and sesame seed (Sesamum 

 indicum), obtaining a positive test; and rape seed (Brassica campes- 

 tris), white sunflower seed (Helianthus), 10 and cotton seed (Gossy- 

 pium hirsutum), with negative results. Palmer and Kempster (1919c), 

 however, have found that rape seed increases slightly the color of the 

 egg yolk when fed to laying hens, indicating the presence of some 

 xanthophyll in the seeds. Refined, but unbleached, cottonseed oil is 

 characterized by a rich golden color and Palmer's (1914g) study of 

 the character of the pigments of cottonseed meal has shown that this 

 color is due to a mixture of carotin and xanthophylls. Hemp seed 

 (Cannabis sativa) was found by Palmer and Kempster (1919c) to 

 slightly increase the color of egg yolk, and thus appears to contain 

 xanthophyll in small amounts. 



The cereal grains also appear to contain carotinoids more or less 

 abundantly. Thudichum (1869) classified the pigment of yellow 

 Indian corn (Zea mays) with the luteins. The author's (1914g) study 

 of this pigment, however, shows it to be almost entirely xanthophyll, 

 with a little carotin. Spectroscopically the xanthophyll corresponded 

 with the principal xanthophyll (probably xanthophyll a) of the chloro- 

 plastids, but its relative solubility and adsorption properties were at 

 variance in that it did not seem to be adsorbed to any extent from 

 petroleum ether or carbon disulfide by CaC0 3 , and it appeared to be 

 just as readily extracted from 80 per cent alcohol by petroleum ether 

 as from the latter solvent by fresh 80 per cent alcohol. The peculiari- 



10 The particular variety of sunflower seed examined is not clear. The common sun- 

 flower (Hcliaiithux iiiiitiixt whose seed is used for commercial oil production, gives a 

 very pale yellow or greenish-yellow oil and it is possible that carotinoids may not be 

 present. 



