Chapter 



8 



Pathways in Biological 

 Nitrogen Fixation 



By PERRY W. WILSON 



Modern researches dealing with the chemi- 

 cal and enzymatic mechanisms of the process of biological 

 nitrogen fixation have been thoroughly summarized, re- 

 viewed, compared biochemically, and reappraised in re- 

 cent years (16, 17, 18). This paper is concerned, therefore, 

 not with chemical or enzymatic pathways, but with the 

 research pathways explored by investigators in this field 

 during the last quarter century. An examination of such 

 pathways may be instructive if they lead upward toward 

 greater understanding, as I hope they do, or amusing if 

 they lead toward even more confusion, as some of you may 

 suspect. 



The manner in which research in this field has been 

 directed and controlled by the techniques available to the 

 investigator is impressive. In retrospect, it is a little shock- 

 ing to realize that a case at least can be made for the thesis 

 that we have been almost prisoners of our methods, and 

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