Chlorocruorin 



coloured pink by haemoglobin. In the blood, as one might expect, 

 there is chlorocruorin. No muscles or other cells of any animal have 

 been found to contain chlorocruorin. 



Most animal cells contain protohaem (Keilin). It is therefore of 

 particular interest to know whether — apart from Potamilla — the 

 tissue cells of animals with chlorocruorin dissolved in their blood 

 contain chlorocruorohaem or protohaem. In Sabella spallanzanii and 

 Protula intestinum, the biggest available animals with chlorocruorin 

 in their blood, no chlorocruorohaem can be found in tissues : the 

 muscles, eggs and sperm contain protohaem alone. Chlorocruoro- 

 haem must, of course, be synthesized somewhere to supply the blood, 

 but we do not as yet know where. 



Received July 1948 



REFERENCES 



1 Fox, H. Munro Proc. roy. Soc. B, 99 (1926) 199 



2 Fischer, H. and von Seemann, C. Hoppe-Seyl. Z. 242 (1936) 133 



3 — and Deilmann, K. O. Hoppe-Seyl. Z. 280(1944)186 



4 Fox, H. Munro Proc. roy. Soc. B 115 (1934) 368 



5 — Ibid 111 (1932)356 



9 — J. exp. Biol 21 (1945) 161 



7 — Nature, Lond. 162(1948)20 



8 — Nature, Lond. 160(1947)825 



293 



