416 MAEION P. NEWBIGIN. 



" enterochlorophyll " when this band is present, and the spec- 

 trum of true chlorophyll, I believe to be merely a striking co- 

 incidence, emphasising the danger of relying upon spectroscopic 

 observations unsupported by chemical investigation, rather 

 than indicating true affinity. In view of these facts Prof. 

 Lankester suggests the emendation '' enterochlor," or '' ente- 

 roverdin," in place of the term '' enterochlorophyll,^' but it is 

 to be noticed that neither in the natural condition nor in 

 solutions is the greenness of the pigment at all well marked, 

 except after the addition of acid. 



Characters of the Associated Lipochrome. — Al- 

 though the yellow pigment found in company with entero- 

 chlorophyll was not subjected to a detailed examination, it may 

 be useful to point out in what respects its presence modifies the 

 reactions of enterochlorophyll. In the first place it modifies 

 the spectroscopic characters, in that it produces marked 

 absorption of the violet end, and so blurs the fourth band of 

 enterochlorophyll, that is the band in the neighbourhood of 

 the F line. Like other yellow lipochrome pigments, it is de- 

 colourised by the addition of hydrochloric or other acids to 

 the alcoholic solution. The result is that the addition of acid 

 makes the fourth band of enterochlorophyll distinct by dimin- 

 ishing the absorption of the violet. The yellow pigment also 

 exercises a marked and often very puzzling eff'ect on the colour 

 of the solutions. When it is virtually absent solutions of 

 enterochlorophyll, like those of chsetopterin, turn blue on the 

 addition of acid, though the tendency for the blue to pass into 

 green is much stronger in the former than in the latter. When 

 the yellow pigment is present acid turns the solution green 

 without trace of blue. The reason for this is that though the 

 yellow pigment is destroyed by acid, yet the amount of acid 

 necessary to completely remove it is also sufficient to turn the 

 enterochlorophyll solution green instead of blue (cf. chaeto- 

 pterin, p. 396). It is exceedingly difficult to remove the yellow 

 pigment from solutions of enterochlorophyll, for although 

 acid decolourises it, the colour returns on the addition of 

 alkali, so that the pigment is liable to appear at very unexpected 



