GREEN PIGMENT OP INTESTINAL WALL OF H.TITO PTEI{ US. 447 



On the Green Pigment of the Intestinal Wall 

 of the ]^nnelid Chsetopterus. 



By 



E. Rny L.aiikestei', M.A., L,L..D., F.R.S., 



Liuacre Professor, and Fellow of Meitoii College, Oxford. 



With Plates 34—37. 



I. Introduction. 



In the year 1864 I obtained specimens of Chsetopterus 

 variopedatus, Renier (at that time called C. insignis by 

 Baird), when collecting at Herm in the Channel Islands. 



My specimens preserved in alcohol gave to the spirit a 

 strong blackish-brown coloration, and the fluid was observed 

 to have a deep red fluorescence. I showed the coloured fluid 

 to Professor Stokes, of Cambridge, where in 1864 I was an 

 undergraduate, and he rapidly examined it with a direct-vision 

 spectroscope. He pointed out to me the remarkable absorp- 

 tion bands which the fluid caused in tlie spectrum of light 

 passed through it, and expressed the opinion that these were 

 similar to if not identical with those caused by some solutions 

 of chlorophyll. In view of the fact that the colouring matter 

 was soluble in alcohol and caused a red fluorescence, as well 

 as a banded absorption spectrum resembling that of chloro- 

 phyll. Professor Stokes was of the opinion that the source of 

 the colour was probably to be found in chlorophyll swallowed 

 by the marine worm which had been immersed in the spirit. 



A year or two later I acquired a Sorby-Browning spectro- 

 scope of my own, and becauie familiar with the absorption 

 spectra of chlorophyll, of haemoglobin, of turacin, and many 



VOL. 40, PART 8. — NEW SER. H H 



