370 JOHN p. FULTON, JR. 



capable of absorption into tho animal body without, being 

 materially changed in the process. Hence if animals employ 

 chlorophyll in building up their pigments, they have it on hand 

 unchanged by the processes of digestion. This conclusion is 

 strongly reinforced by more recent work. Dhere et Vegezzi 

 (1916) have shown that all of the chlorophylloid pigments pass 

 without change into the liver of Helix pomatia. But the 

 more important work is that of L. S. Palmer (191/5, 1916), 

 who has shown that certain plant pigments are absorbed from 

 the intestine into the blood of a cow and from there pass un- 

 changed into the milk. This investigation will be discussed 

 in greater detail under carotin (p. 373). One is reminded at this 

 point of the observations of Moglia (1910), that the depth of 

 coloration in certain gastropods decreases in the winter, due 

 as he believes to a lack of food, and also of M. E. Johnson's 

 (1913) contention that Eana depends for its colour, not upon 

 the amount of nutrition but upon being nourished by food 

 substances which are properly pigmented. 



MacMunn (1S83 c) has shown that in certain molluscs — as 

 Patella — a haematin is present in the liver in addition to 

 enterochlorophyll, and there is every probability he adds, that 

 the haematin finds its origin in that tissue. Though the haema- 

 tin mightr have arisen independently of the chlorophyll in the 

 liver, the more logical assumption (in view of the chemical 

 similarities between chlorophyll and haematin, alluded to in 

 Part I of this study) is that it is derived from the chlorophyll. 

 As with the origin of echinochrome, the origin of molluscan 

 haematin is highly uncertain, but the hypothesis just presented 

 is interesting and certainly merits further investigation. 



From the observations of Paladino (1910) one is led to 

 believe that haematin is present not only in molluscs but likewise 

 in the livers of certain crustaceans. Apparently unacquainted 

 with MacMunn's work Paladino has reported the presence of 

 a water-soluble ferruginous pigment in the livers of several 

 crayfish. In addition, he finds a yellow lipochrome (probably 

 carotin) which contains no iron. The iron-containing pigment 

 which he finds is undoubtedly either haematin or a derivative. 



