144 CAROTINOIDS AND RELATED PIGMENTS 



that it was derived from the yellow pigment which colors the adipose 

 tissue of many birds) or by the methods which Krukenberg found it 

 necessary to use in extracting the pigment from the feathers. It is 

 well known that the spectroscopic properties of the carotinoids are 

 among the first to be affected adversely. 



Zoonerythrine was found to be the cause of the color of the red 

 feathers of the following birds: C alums auriceps, Catinga coerulea, 

 Phoenicoptenis antiquorum (flamingo), Cardinalis virginianus (the 

 cardinal bird) , Pyrocephalm rubincns, Phlegoenus cruenta (the dagger- 

 stab pigeon of Luzon), Trogon Massera, Paroaria cucullata, Picus 

 major, Pyrrliula rulgaris (bullfinch), tigerfinch, Megaloprepia mag- 

 nifica, Cymbyrhynchus makrorhynchus, and possibly Ithaginus cruen- 

 tatus. The red feathers of the parrots, Eclectus polychlorus and 

 Cacatura roseicapilla, contained the pigment as did also the yellow 

 feathers of the bird of paradise Xanthomelus aureus. In addition, 

 Krukenberg (1882m) lists 14 species of Picides (woodpeckers) whose 

 red pigment is rhodophane. 



Among the yellow feather pigments Krukenberg mentions zooful- 

 vine, coriosulfurine, paradiseofulvine, picofulvine and psittacofulvine, 

 believing, as is evident from the names, that the b.i*"^ of paradise, the 

 woodpeckers and the parrots contained, in some cases, special yellow 

 pigments besides the general ones listed first. Of these the special 

 parrot pigment, psittacofulvine, is evidently not even a lipochrome in 

 the broad sense, from the description given. Paradiseofulvine, found 

 in the yellow neck feathers of the male Diphyllodes magnified, and 

 the yellow head, neck and back feathers of the male Paradisea 

 papuana and P. mbra, was extractable only after digestion of the 

 feathers with alkali or trypsin. Save for complete absence of absorp- 

 tion bands it was identical with coriosulfurine. These facts suggest 

 that the treatment necessary to extract the pigment altered its spec- 

 troscopic properties, a supposition confirmed by Krukenberg's own 

 observation that heating zoofulvine in an alkaline fluid destroyed its 

 absorption bands. 



The properties of zoofulvine and coriosulfurine are so nearly identi- 

 cal, differing only by a slight shift in absorption bands, that their 

 separate entity is very improbable. Krukenberg believed that the 

 former was derived from the latter. Both pigments were readily ex- 

 tracted from the finely divided feathers by hot alcohol or fat solvents. 

 Krukenberg stated that coriosulfurine withstood saponification better 

 than zoofulvine but gave a less distinct color reaction with con. H 2 S0 4 . 



