ON CERTAIN GREEN PIGMENTS IN INVERTEBRATES. 411 



thus a slight ambiguity in the use of the term enterochlorophyll, 

 for it is not quite apparent whether it is to be used to designate 

 the pigment contained in the yellowish extract of molluscan 

 liver, which gives a three-banded spectrum, or to that in the 

 green solution produced by the addition of acid to this solution, 

 which has a five-banded spectrum. 



In his second paper Dr. INIacMunn applied the method of 

 saponification to the pigment, and showed that solutions of his 

 euterochlorophyll, like solutions of plant chlorophyll, contain a 

 yellow lipochrome pigment in addition to a greenish constituent. 

 In the case of plant chlorophyll it is now known that the associa- 

 tion of '^chlorophyll green" and the lipochrome, xanthophyle, 

 is merely incidental, and the term chlorophyll is restricted to 

 the former. It is not quite clear whether Dr. MacjMunn regards 

 " enterochlorophyll ^' as a combination of a lipochrome and a 

 green constituent, or whether he regards them as associated 

 pigments ; but he was not able to obtain complete separation, 

 and believes that " in euterochlorophyll there is probably a 

 more intimate union between the constituents than in plant 

 chlorophyll.'^ 



Krukenberg's (2) observations are much less detailed. He 

 found in the " bile " of MoUusca what he regards as evidences 

 of three pigments. One of these, he says, is a lipochrome, and 

 gives two bands in the violet ; another gives a strong band in the 

 red and one in the green, and is a " hepatochrome :'' a band at 

 the beginning of the green appeared in some of his solutions 

 and puzzled him greatly, but he believed that it belonged to a 

 third unknown pigment. He evidently worked with very small 

 amounts of pigment, and did not go beyond this point. In- 

 complete as the observations are, however, Krukenberg was 

 right in every one of his inferences. The bands in the red and 

 the green are two of the bands of " enterochlorophyll ;" the 

 occasional baud in the beginning of the green is that band of 

 enterochlorophyll which is only distinct in acidified solutions ; 

 the violet bands are due to the presence of an additional yellow 

 pigment. 



