Further observations on enterochlorophyll, and allied pigments / by C.A. Mac Munn.

  • MacMunn, Charles Alexander, 1852-1911.
Date:
1886
Catalogue details

Licence: Public Domain Mark

Credit: Further observations on enterochlorophyll, and allied pigments / by C.A. Mac Munn. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    rayed Solaster the dominant band of an absolute alcohol solution of the radial coeca— which was yellow and fluoresced red—extended from X 669 to X 657. Other speci- mens were examined with the same result, their radial coeca furnishing only a small amount of enterochlorophyll. No enter ohsematin could be detected; and in none of their integuments was hsematoporphyrin found. A full account of the integumental colouring matters is reserved for another communication. Uraster rubens.—A great number of this species have been examined, and the results obtained are so important in deciding the question as to the animal origin of enterochlorophyll, that I think it necessary to give the results in greater detail than in other cases. (1) Uraster with a nodulated integument.—A filtered alcohol extract of the coeca was a dull sap green, and showed a red fluorescence and two well-marked bands, and a feeble third in a deep layer ; also in a shallow layer an ill-defined band at the blue end of green. The bands read :—1st, X 669 to X 640 ; 2nd, X 620‘5 to X 591. With nitric acid the spectrum changed, and the hands read:—1st, X 665 to X 640 ; 2nd, X618toX591; 3rd, X 579 to X 557 (?). The great breadth of the band in red is here noticeable. (2) Uraster with a red integument.—Here the alcohol extract of the radial coeca was greenish, fluoresced red, and gave the same kind of band in red as (1), hut after this solution had stood twelve hours the band in red could be no longer seen, and the colour of the solution had changed to orange-yellow. The residue left after evapora- tion of the alcohol was a pale, vellowish-brown colour, and dissolved in chloroform showed one faint band in the blue part of green. Hence it would appear that the enterochlorophyll in this case spontaneously changed into another colouring matter ; the amount of material was, however, too small to enable me to determine what this colouring matter was. (3) A violet Uraster.—The radial coeca yielded when extracted with alcohol a deep gamboge-yellow coloured solution, showing a badly-marked hand in red, corresponding in position with the above-mentioned band, but showing a strong absorption of the violet end of the spectrum up to E. In a thin layer a broad ill-defined shading from X 516 to beyond X 47 5 became detached. On adding nitric acid a distinct blue colour was produced, the hand in red moved nearer the violet, and the broad shading could be no longer seen. Caustic soda did not cause this shading to disappear. There is no doubt that these coeca contained a colouring matter which belongs to the lipochromes, and I believe it is more like Kuhne’s rhodophan or xanthophan than anything else. Now, as we find in the integument a similar pigment, there can no longer be a doubt that the integumental pigment (as I formerly showed) is prepared in the radial coeca. (4) A reddish-brown Uraster.—The radial coeca when extracted with alcohol furnished a dark-yellow solution with a red fluorescence. This showed spectrum 17, Chart I., the result of combining the spectrum of a deep and shallow layer. The bands read :—1st, X 667 to X 649 ; 2nd, X 611 to X 593 ; and 3rd, X 541’5 to X 529‘5.
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