CAROTINOIDS IN THE VERTEBRATES 145 



Both were very sensitive to action of light. The position of their 

 absorption bands, as pictured by Krukenberg, is practically identical 

 and resembles xanthophyll very strongly. The identity of the zooful- 

 vine and egg yolk spectra was noted by Krukenberg himself, and inas- 

 much as coriosulf urine is stated to be the pigment found in the beaks, 

 shanks, skin and fatty tissue of fowls and geese, as well as in certain 

 feathers, there is no reasonable doubt left that the two pigments arc 

 the same and are none other than the xanthophyll met with in fowls. 



The birds whose feathers owe their color to this xanthophyll are 

 as follows: The yellow feathers of Euphone nigricollis, the golden 

 feathers of Oriohis galbula, the yellow feathers of the canary Fringilla 

 canaria, the yellow feathers of the parrot Aprosmictus melanurus, the 

 yellow and green feathers of Certhiola mexicana, and Chlorophanes 

 atricapilla, the green feathers of the male parrot Eclectus polycMorus, 

 the orange feathers of the great red macaw Sittace Macao, the yellow 

 ornamental feathers of the male Paradisea papuana, the yellow and 

 orange feathers of Xanthomelus aureus and Selencides alba and the 

 feathers of the woodpeckers Chrysoptilus punctigula, Chloronerpes 

 aundentus, C. Kirkii, Dendropicus cardinalis, Campethera nitbica, 

 Tiga tridactyk Dryocapus auratus, Colaptes auratus, and C. 

 olivaceus. 



The yellow picofulvine described by Krukenberg (1882m) in a num- 

 ber of species of woodpeckers, differs from the pigments just described 

 in its yellowish-green color in ether and CHC1 3 , in its orange (not red- 

 orange) color in CS 2 , in its lower solubility in petroleum ether, and by 

 the fact that its absorption bands are in a characteristic position, 

 shifted so greatly towards the violet from the bands of coriosulf urine 

 that error of observation seems excluded. One is reminded strongly 

 of the xanthophyll (3 of Tswctt, and is tempted to suggest, provision- 

 ally, that a concentration of this carotinoid in the feathers of these 

 birds is responsible for the pigmentation. 



Carotinoids in Fishes 



Observations on the pigments of fishes have been confined almost 

 entirely to those of the skin, namely, to the causes of surface colors. 

 The body tissues have been examined in only a few instances. The 

 surface colorations may be likened in many respects to the feather 

 colorations of birds. The pigments involved appear to be almost 

 wholly reds, yellows and blacks, combined (in a physical sense) in 



