CONTRIBUTIONS TO ANIMAL OHROMATOLOGY. 95 
lipochromes are so similar, there cannot be a great difference 
between them. 
Besides occurring in green leaves, they are also found in 
yellow flowers and fruits, &c. ; and there is no doubt that such 
pigments as phycoxanthine, peziza xanthine, orange xantho- 
phyll, xanthophyll, yellow xanthophyll, fucoxanthine, and 
others, are all lipochromes. As to animals, Krukenberg states 
that the lymphatic fluids! and various secretions of Vertebrates 
and Invertebrates, the vertebrate retina, the corpora lutea, 
the egg-yolks of different species of animals, the yellow, green, 
or red pigmented integuments of various Invertebrates and of 
Vertebrates from fishes to birds, owe their colouration, with 
few exceptions, to dissolved, granular, or diffusely distributed 
lipochromes. They are, however, wanting apparently in the 
colourations of the epithelial structures of mammals, and in 
birds’ eggshells. 
Again, they only occur in traces among snakes; although 
among birds, amphibians, and fishes, the different organs are 
permeated with lipochromes. 
I referred above to the “ lipochromoids ;” these, according 
to the same observer, are present with “ melanoids” in the 
stems of Gorgonide, the shells of Mollusca, and they lead 
directly to the black pigments known as melanins; but the 
description of all these is so extremely vague that it would be 
wasting space to quote Krukenberg’s remarks on them. The 
truth is, we do not know enough about the connexion be- 
tween these pigments to allow us to make any sweeping 
generalisation at present. 
It is unnecessary to recapitulate my own results, they are 
commented upon where necessary in the former part of this 
paper. I regret that they are not more valuable or more 
striking, but such as they are they may be found useful for 
purposes of comparison. 
1 Cf. Poulton’s interesting observations on “The Essential Nature of the 
Colouring of Phytophagous Larve, &c.,” ‘Proc. Roy. Soc.,? No. 237, 1885. 
VOL, XXX, PART 2,——NEW SER. G 
