PROVOCATIVE BIOLOGICAL THEORIES 91 



We must keep our eyes open eternally for the part 

 that selective elimination plays in the most fundamental 

 of biological problems — the formation and transforma- 

 tion of biological systems — "for here it plays the mas- 

 ter role." 



^Buchanan, J. William, "Some Limitations of Warburg's Theory of the Role 

 of Iron in Respiration," Science, Sept. 9, 1927, p. 238. 



^Jennings, H. S., ''Biology and Experimentation," Science, July 30, 1926, 

 pp. 97-105. 



