THE FOOD QUESTION 



But if each kind of cell in the body has 

 its own chemistry, we may well be stag- 

 gered at the infinite number of shapes and 

 forms which vital chemistry assumes. 

 Thus we must have a different and special 

 chemio-taxis for the cell which is helping 

 to make a toe nail from one which is 

 building up a centre for sight in the brain 

 cortex, and then untold thousands more 

 of varying kinds of chemio-taxis the body 

 over. 



It is the frequent recurrence of such 

 embarrassing conclusions which is making 

 many of the younger biologists weary with 

 all physico-chemical explanations of life. 

 As J. E. Haldane, M.D., F.R.S., Profes- 

 sor of Physiology in the University of 

 Oxford, remarks : " As a matter of fact, 

 the physico-chemical theory of life has not 

 worked in the past and can never work. 

 Those who aim at physico-chemical ex- 

 planations of life are simply running their 

 131 



