ANIMAL CHLOROPHYLL 371 



Lipo chromes. — Halliburton (1885), in an investigation 

 of the blood of decapod Crustacea, found a red lipochrome 

 present in addition to haemocyanin, which had been described 

 previously. He extracted the red substance by first precipitat- 

 ing the proteins of the blood with alcohol and then extracting 

 the red pigment with ether. He noted also that the amount 

 of the red pigment varied in different specimens, but was 

 unable to find an explanation for the fluctuation. In the same 

 year MacMunn (1885 a) investigated Halliburton's red lipo- 

 chrome and concluded that it was identical with the pigment 

 of the chromatophores in the exoskeleton. Several years later 

 Miss Newbigin (1897) reinvestigated the question. She corro- 

 borated MacMunn's results, but in addition found evidence 

 that the red lipochrome was derived from the yellow pigment 

 (probably the carotin contained in the enterochlorophyll ; 

 see below, p. 873) of the liver. Consequently, if Miss Newbigin's 

 results are reliable, one would trace the origin and development 

 of the red pigment in the chromatophores of crustaceans as 

 follows : chlorophyllous substances enter the body as food ; 

 they are absorbed by the intestine and stored by the liver, 

 in which tissue they probably undergo slight modification. 

 The carotin contained in the chlorophyll of the liver, when called 

 upon, is transformed into a red pigment substance — a lipo- 

 chrome — and transported by the blood to the epidermis, where 

 it is used in building up the chromatophore. The recent 

 analyses of Verne (1920) have shown that the red pigment of 

 the decapod Crustacea is a hydrocarbon identical chemically 

 and spectroscopically with vegetable carotin, and possess the 

 same empirical formula (C4Q H^q). This investigation removes 

 any doubt which may have existed regarding the identity of 

 the two pigments. 



The fact that the red lipochrome present in the blood is 

 subject to great fluctuation (Halliburton), is possibly to be 

 explained by the moulting period of the animal. Immediately 

 after the moult there is great demand for pigment to build 

 up new chromatophores, which results in a diminution of the 

 amount present in the blood. In this connexion the recent 



