CHEMICAL RELATIONS BETWEEN CAROTINOIDS 181 



Escher's study of the comparative melting points of ovarian, carrot 

 and leaf carotin shows that slight differences between the melting 

 point of different carotinoids are not significant unless the determi- 

 nations arc carried out simultaneously. 



The recent work of Verne (1920) on the identity of the red crus- 

 tacean chromolipoid with plant carotin throws doubt on the results of 

 numerous previous workers which indicate that the pigments are 

 related but not identical. 



