inconceivable how heredity could be accomplished by any 

 other method, and yet there is not a textbook of biology 

 in existence which contains a clear statement of this 

 proposition ! On the contrary, as late as 1935 we read in 

 The Philosophy of a Biologist by J. S. Haldane the 

 following disheartening statement: 



We can form no conception on these lines [of the 

 prevailing mechanistic conception of physics and 

 chemistry] of how it is that a living organism, pre- 

 suming it, as we must on the mechanistic theory, to 

 be an extremely complex and delicately adjusted 

 piece of molecular machinery, maintains and adjusts 

 its characteristic form and activities in the face of 

 a varying environment and reproduces them indefi- 

 nitely often, (p. 37.) 



It will not be necessary to make any lengthy comments 

 on the above quotation of Haldane, because the very 

 language he uses shows a deplorable lack of familiarity 

 with modern scientific concepts. No present-day mech- 

 anist tries to maintain that the living organism is merely 

 a piece of ''molecular" machinery. There are several 

 other types of chemical structure besides the "molec- 

 ular" structure, and in living matter it is principally 

 the nonmolecidar structures which control biological ac- 

 tivities. 



Statements that science cannot explain this or that on 

 a mechanistic basis, although seldom made by scientists, 

 are frequently heard emanating from the pulpits. Since 

 statements of that sort constitute direct attacks upon 

 science, it becomes not only the privilege but also the 

 duty of scientists to make their reply. The fallacy of all 

 such statements about the supposed limitations of sci- 

 ence lies in the fact that living matter, as it exists in the 

 cells of the higher animals, is itself complex beyond com- 

 prehension, and therefore cannot be said to lack the nec- 

 essary complexity to account for the manifold activi- 



