viii Contents 



PAGE 



Part II— HEMOGLOBIN AND METABOLIC DERIVATIVES 



Chairman : [Sir Charles Harington, PhD, frs 

 Editor : C. Rimington, PhD 



The biosynthetic mechanism of porphyrin formation 



D. Shemin, PhD, and J. Wittenberg, phD. Dept. of Bio- 

 chemistry, Columbia University, New York ... 41 



Discussion 



A. Neuberger, D. Shemin, H. G. Wood, K. Bloch, C. 

 Rimington, D. Rittenberg, S. Gurin .... 64 



Studies on mammalian red cells 



A. Neuberger, md, PhD, frs. National Institute for Medical 

 Research, London . . . . . . .68 



Discussion 



B. Thorell, a. Neuberger, A. Wormall, D. Ritten- 

 berg, P. L. Mollison ...... 82 



Preliminary investigations for a study of energy utilized 

 by the surviving fowl erythrocyte in haem synthesis 



C. Rimington, PhD, Dept. of Chemical Pathology, University 

 College Hospital, London ...... 86 



Discussion 



D. Shemin, C. Rimington, H. G. Wood, H. A. Sloviter 89 



Iron metabolism in pathological conditions 



A. Vannotti, md, Clinique M^dicale Universitaire, Hopital 

 Cantonal, Lausanne ....... 90 



Discussion 



A. S. McFarlane, a. Vannotti, K. Aterman, J. E. Falk 94 



Part III— USE OF TRACERS IN THE STUDY OF 

 BIOLOGICAL EFFECTS OF RADIATION 



Chairman: Sir John Cockroft, frs 

 Editor : L. H. Gray, ma, PhD 



The modification of X-ray sensitivity by chemicals 



A. HoLLAENDER, PhD, G. E. Stapleton, and W. T. Burnett, 

 Jr., Division of Biology, Oak Ridge National Laboratory, 

 Tenn 96 



