DR. C. A. MACMUNN ON ENTEROCHLOROPHYLL, AND ALLIED PIGMENTS. 241 
enterohcematin be examined quickly , the two bands of the reduced pigment can be 
seen; on exposure to air tliey fade away, to be again brought back by reducing 
agents. Caustic alkalies, no doubt, also cause the bands to appear, but this is 
no argument against reduction and oxidation. The impropriety of calling this 
pigment “ helicorubin ” is patent when we consider that it is not limited to Helix , but 
occurs in Limax, Arion , Astacus, and Patella, &c., as has been shown by me. I have 
tried to convert it into hsematoporphyrin, but hitherto with only partial success ; but 
I had not enough material to work upon. It is a very unstable body, resembling 
in this respect Professor Lankester’s chlorocruorin. As I have already said, it is 
probably the mother-substance of those liistohsematins, which are found in animals 
in whose “livers” it is built up. Another view might be held, namely, that it is an 
excretion and represents the form in which the above colouring matters are got 
rid of, but its very instability is against that view. 
Echinodermata. 
It will be seen that the dominant band of chlorophyll in solutions of the radial coeca 
of starfishes is sometimes replaced by two narrow ones # in the same part of the 
spectrum ; I believe this has been noticed among plants in the case of very young 
green leaves, but I am unable to find the reference to this statement. It would seem 
to show that, as an examination of a considerable number of the same species teaches, 
one meets with enterochlorophyll in all stages of manufacture; in some cases immature 
and having just been formed, or in stages of preparation ; in other cases fully formed, 
when it more nearly approaches the condition of plant chlorophyll. 
Solaster p>apposa and other species. —The first specimen examined was a brilliant red 
colour, which colour was due to a pigment having a close resemblance to zoonerythrin 
(= tetronerythrin), but in thin layers of its solutions showing two or three bands like 
those of lutein. Hence the pigment cannot be rhodophan t or xanthoplian, and its 
colour shows that it is not chlorophan, so that all one can say is that it is a lipo- 
chrome.j; A rectified spirit extract of the radial coeca (which were brownish) was 
yellow, had a faint red fluorescence, and gave a well-marked chlorophyll spectrum 
(spectrum 16, Chart I.). The three most prominent bands read as follows:—1st, X 669 
to X 651‘5 ; 2nd, X 618 to X 593 (?); and 4th, X 509 to X 490‘5 (?). These measure¬ 
ments are doubtful owing to the small amount of pigment in solution. 
The dominant band in red was found in a fourteen-rayed red Solaster papposa,, 
slightly different from the above, from X 672 to X 651’5 (fie., in an absolute alcohol solu¬ 
tion of the coeca). Its other bands agreed closely with those of the first specimen. Both 
solutions on treatment with nitric acid gave the usual series of bands. In a twelve- 
* This double band in red was noticed also in other cases, e.g., Octopus and Anodonta, &c. 
f See below. 
+ See below. Note the one-banded lipochrome in spectrum 16. 
MDCCCLXXXVI. 2 I 
