CAROTINOIDS IN THE PHANEROGAMS 83 



not very wisely chosen. The name proposed for the pigment by 

 Schnnck (1903), who apparently was unfamiliar with Millardet's 

 investigation, namely, lyropin, is more generally used at present, espe- 

 cially since \Yillstatter and Eschcr (1910) adopted it in their thorough 

 chemical study of the pigment. Duggar (1913) has ni'lered the name 

 Ivcopersiein as being more suitable, but in spite of Duggar's very valid 

 ariiuiiu-nts against the name lyeopin, the latter appears likely to 

 become the prevailing term for the coloring matter. 



Millardet not only obtained the tomato pigment in crystalline con- 

 dition, but also observed the crystals in the flesh of the ripe fruit. 

 The crystalline pigment was described by him as being insoluble in 

 water, soluble in alcohol at higher temperatures, and easily soluble in 

 CS 2 , CHC1 3 and benzene. It showed a characteristic spectrum in 

 CS 2 , showing two bands in the green at B and F, respectively, and a 

 third in the blue between F. and G. It readily bleached in the light. 

 Millardet believed that the pigment was derived from chlorophyll, but 

 this idea has long since been abandoned. 



A. and G. de Negri (1879) regarded the tomato pigment as iden- 

 tical with the rubidin which they isolated from the watermelon. 

 Schimper (1885) observed the red crystals in the ripe tomato fruit, 

 as did also Courchet (1888). Arnaud (1885), however, following his 

 discovery of carotin in the chloroplastids, believed the tomato pig- 

 ment to be carotin. Passerini (1890) followed Arnaud in this belief 

 and so did Ehring (1896), Tammes (1900) and Kohl (1902). Zopf 

 (1895), however, could not identify it spectroscopically with carotin. 

 Schunck (1903), also, found the red tomato pigment to have a char- 

 acteristic absorption spectrum. Schunck believed it to be a distinct 

 pigment, different from carotin, and, as previously stated, named it 

 lyeopin. The same pigment is found in the leaves of the tomato plant, 

 according to Montanari (1904), but this fact has not been reported 

 by other investigators. 



The first hint of the true relation of lyeopin to carotin was obtained, 

 however, by Montanari, who submitted the pure crystals to analysis 

 for the first time. He obtained an average composition of C = 88.14 

 per cent and H - - 10.88 per cent, which he regarded as correspond- 

 ing sufficiently well to the Arnaud formula for carotin, C 20 H 38 , which 

 was still in vogue at that time. Molecular weight determinations in 

 benzene, using the cryoscopic method, gave values of 635-650, from 

 which fact it was concluded that the pigment was dicarotin, or C 62 H 



74> 



