CAROTINOIDS IN THE PHANEROGAMS 85 



the other carotinoids, but the oxidized product has a characteristic, 

 different odor from oxidized carotin, according to Willstiitter and 

 Escher. Especially characteristic is the position of the absorption 

 spectral bands of lycupin, particularly in CS 2 , three bands being vis- 

 ible, the second of which nearly occupies the space between the first 

 two carotin bands. The measurements as carried out by Willstiitter 

 and Escher are as follows, using a 0.05 per cent solution in carbon 

 disulfide. The figures have been confirmed completely by Monteverde 

 and Lubimcnko (1913b). 



10 mm. layer. 20 mm. layer. 40 mm. layer. 



Band I : 554 --540 mi 561 ---555 -536 HH 563 -533 . .525 nn 



Band II : 514 499.4 " 517.5 -498 " 525 -493 . .483 " 



Band III : 479 . .472 " 481.5 468 483 -462.5 . .427- ' 



Note: - means very dark; means fairly dark; . . means rather weak. 



Since Willstiitter and Escher's thorough study of the red tomato 

 pigment, Duggar (1913) has observed that green tomato fruits ripened 

 above 30 C. do not form lycopin but only carotin (possibly xantho- 

 phylls also), producing a yellow fruit, but that the induced yellow 

 fruits form lycopin if the temperature is reduced to the usual ripen- 

 ing temperatures, namely, 20 to 25 C. These facts are of special 

 interest to the plant physiologist and geneticists. 



Of particular interest from the standpoint of those desiring to iden- 

 tify the presence of lycopin in other fruits and plants is van Wis- 

 selingh's (1915) study of the microchemical crystallization of lycopin 

 and the effect of various reagents on the crystals thus formed. This 

 investigator finds that lycopin does not readily crystallize in the 

 tomato fruit by the Molisch method at room temperature, but does so 

 more readily at 80 C., and very readily at 140 C., using a 10 per 

 cent solution of KOH in glycerin instead of in alcohol, the high tem- 

 perature, of course, making the use of alcohol unfeasible. The other 

 carotinoids fail to crystallize at the high temperature. The lycopin 

 crystals which form have a reddish-violet color and show a charac- 

 teristic color change with bromine from red-violet to blue-violet to 

 blue-green, green, yellow, and finally colorless. Like carotin, the 

 microchemical lycopin crystals are insoluble in phenol-glycerin (3 

 parts by weight of phenol crystals and one part by weight of glycer- 

 in). Van Wisselingh also found what appeared to be carotin crystals 

 in the tomato fruit after carrying out the Molisch procedure at 80 C. 



