348 JOHN V. FULTON, JU. 



proved readily soluble ; the condylactid pigment was also 

 dissolved by acetone, but not sp readily. The difference in 

 rate of dissolution is probably to be accounted for by the 

 greater thickness of the Condylactis tissue. Therefore, since 

 the two pigments are found in species of the same order, since 

 they are of the same colour, since in the presence of acid they 

 are uniformly deepened in shade, and since they are each to 

 be extracted by only one (the same one) of nine solvents, it 

 seems reasonable to conclude that the two pigments are identical. 

 Among the earlier autliors the observations of Moseley 

 (187B) upon actinian pigments are perhaps the most significant. 

 He described a red colouring matter (from Actinia mesem- 

 b r y a n the m u m and from B u n o d e s c r a s s i c o r n i s) 

 Avhich ho called ' actiniochrome ' ; I\IacMimn fomid tliis pig- 

 ment insoluble in many of the ordinary sohents for animal 

 pigments.^ All of the solvents which he employed also gave 

 negative results when applied to A. bermudensis and 

 C. passi flora. This suggests that the pigment of the 

 Bermuda actinians is probably identical with Moseley's actinio- 

 chrome, but only a spectroscopic examination can determine 

 this with certainty. The two species worked on by Moseley 

 were subsequently investigated by MacMunn (1885 c) with the 

 result the Moseley's actiniochrome was identified, but, in 

 addition, a haematin-yielding pigment was isolated and given 

 the same ' actiniohaematin '.- This pigment, which, it should 

 be emphasized, is closely related to haemoglobin, performs 

 a respiratory function, being capable of existing in a state 

 both of oxidation and reduction. On finding these two pigments 

 together in one animal MacMunn drew the conclusion that one 

 is a respiratory substance (actiniohaematin), and that the 

 other (actiniochrome) is purely for ornament. The most 

 notable contribution of MacMmm, however, was his observa- 

 tion concerning the relation of Zooxanthellae (' yellow cells ') 



^ MacMunu (1885 c, p. 643), alcohol, ether, chloroform, and carbon 

 bisulphide. 



^ This pigment, on treatment with a metalUc hAdroxide and sodium 

 sulphide, gives haemochromogen which on oxidation gives haematin. 



