CONTRIBUTIONS TO ANIMAL OCHROMATOLOGY. 65 
slightly darkened and otherwise unchanged by nitric acid. 
No lipochrome was therefore present. 
The absorption bands in these solutions were made more 
faint by caustic potash, probably by precipitation, although the 
yellow colour and the green fluorescence were still present. 
With an excess of hydrochloric acid the green fluorescence and 
the bands still persisted, the fluid remaining yellow. So far, 
then, as these incomplete observations will allow one to con- 
clude I can see no reason for considering this pigment as 
belonging to the “uranidines.” It is quite different from the 
pigments called by that name among the Sponges. 
I cannot help thinking that Krukenberg has confused this 
yellow fluorescent substance with another which may be 
present “‘in unreinen Gewebsauszugen,” and which “ sich sehr 
rasch zersetzt.” 
In the little Holothurian Ocnius brunneus the ovaries are 
pale blue instead of the brilliant red of Holothuria nigra, but 
they show a feeble shading at the blue end of green correspond- 
ing with that seen in the red ovaries of H. nigra; on placing 
them in alcohol or ether they turn red and yield a lipochrome 
to solvents. Here evidently a very sensitive colouring matter is 
present, a lipochromogen, which under very slight influences 
becomes changed into a lipochrome. In the larval lobster a 
similar pigment occurs which turns red in alcohol, &c., and 
the “ cyano-crystals”’ of Crustaceans are evidently of the same 
nature. One can hardly suppose that any chemical change 
can take place here except it be a dehydration or a feeble oxi- 
dation. An immense number of marine animals contain at an 
early and some at a late stage of their life such sensitive- 
chromogens, and the study of their colour changes would pro- 
bably yield interesting results. 
Asterias glacialis.—In the integument of starfishes I have 
found lipochromes and hzmatoporphyrin,! the latter in brown 
specimens. In Asterias glacialis a violet pigment is present ; 
1 “Studies in Animal Chromatology,” ‘Proc. Birm. Philos. Soc.,’ vol. iii, 
1883; and “On the Presence of Hematoporphyrin in the Integuments of 
Certain Invertebrates,” ‘Journ. Physiol.,’ vol. vii, No. 3. 
