327 



the band nearest the violet grows faint. In all these respects the pig- 

 ment shows a marked resemblance to enterochlorophyll while it dif- 

 fers from chaetopterin chiefly in the presence of a considerable amount 

 of yellow (lipochrome) pigment in the solution, and possibly of other 

 pigments. 



The blue acid solution left after precipitation of the dark pigment 

 contains the same pigment as the precipitate, but in a purer condition 

 without intermixture of lipochrome. To this blue solution pieces of 

 marble were added and, after the effervescence had subsided, a dark 

 green precipitate was found at the base of the beaker. This dissolved 

 in methylated spirit to form a dark greenish-brown solution with strong 

 red fluorescence, which give a magnificent spectrum with four bands. 

 The centres of the bands showed the following positions: 

 I, I 668, II, I 612, III, I 537, IV, I 506. 



This spectrum is almost identical with that of the enterochloro- 

 phyll of the limpet. 



When acid is added to this solution it becomes a dusky-blue while 

 still retaining its red fluorescence. The spectrum also changes, a new 

 band appearing between II and III of the original spectrum; the ori- 

 ginal fourth band also disappears while the other bands undergo a 

 slight change of position. The centres of the bands are as follows : 

 I, ;. 663, II, I 610, III, I 572, IV, I 534. 



A further addition of acid causes the solution to turn green , the 

 bands at the same time growing faint. In these changes both of 

 colour and spectrum the pigment closely resembles purified entero- 

 chlorophyll and chaetopterin. 



The dry pigment is soluble in ether as well as in alcohol. 



Conclusions: While acid acts on an alcoholic extract of green 

 leaves in such a way as to produce the pigment phyllocyanin which 

 is insoluble in alcohol and ether, its action on an alcoholic extract of 

 green Algae results in the production of a pigment which is exceedingly 

 soluble in alcohol, and does not therefore precipitate from acidified 

 alcoholic solutions unless a considerable amount of water be added. In 

 its colour and fluorescence in its spectrum, in its changes in colour and 

 spectrum on the addition of acid, in its solubilities, the pigment shows 

 a remarkable resemblance to the enterochromes. This resemblance is 

 such that, taken in conjunction with the recent observations and con- 

 clusions of Dr. McMunn in the case of »enterochlorophyll«, and 

 with the fact that that pigment occurs in the faeces of Patella^ it 

 seems to justify the conclusion that » enterochlorophyll (f at least is an 

 acid derivative of chlorophyll, produced by the action of the digestive 



