214 PHYSIOLOGY OF THE INVERTEBRATA. 



its mesoderm and elsewliere a colouring matter nndistinguisli- 

 able from biliverdin " of the Vertehrata. As biliverdin is 

 derived from the decomposition of Vertebrate hemoglobin, 

 its presence in Actinia is further proof that these organisms 

 contain pigments closely allied to haemoglobin. 



MacMunn has proved that the hsematin-yielding pigment 

 of A. mesemhryanthemum is not the same as Prof. Moseley's 

 actiniochrome, although the latter pigment is present ia 

 certain species of the Actinim. The band of actiniochrome is 

 nearer the red than that of MacMunn's pigment (actinio- 

 haematin), and the two pigments yield entirely different 

 decomposition products under similar treatment. After a 

 careful examination of the glycerol extracts, MacMunn found 

 that " every specimen of Actinia mesemiryanthemum, -whether 

 its colour was red, reddish-brown, brown, or greenish-brown, 

 gave to the glycerol, after some days' extraction, a certain 

 amount of colouring matter, which in every case could he 

 made to change into hemochromogen, while actiniochrome 

 never could be changed into it; hence the respective pig- 

 ments are very different. One is a respiratoiy colouring matter 

 (actiniohsematin), the other (actiniochrome) is an ornamental 

 one." 



The glycerol extract made from the ectoderm of an anemone 

 yielded actiniohsematin, which, on the addition of potassium 

 or sodium hydroxide and ammonium sulphide, was rapidly 

 changed into hsemochromogen. "It appears that this 

 hematin-yielding pigment does not give the same spectrum 

 in brown specimens as in red ; but the spectrum of the 

 glycerol extract of red Actinim has a close resemblance to 

 that of the spectrum of the solid ectoderm and other parts 

 of brown specimens. This does not show that the pigment 

 has been altered by extraction with glycerol, but its mole- 

 cular condition may be altered. It is well known that the 

 spectrum of a pigment may differ in the solid and liquid 

 state without any necessary change in its composition (Vogel 

 and Kundt)." 



