The Microbe as a Whole 11 



pied with a particular problem, into a pattern that initiates 

 a new line of attack. Until this stage is reached, advance 

 in new directions depends exclusively on individual effort. 

 Although it is clear that our knowledge of various micro- 

 bial degradations that have not yet been investigated in 

 detail could readily be brought up to the level of under- 

 standing achieved in other cases by having teams of enzy- 

 mologists, biochemists, and microbiologists work on the 

 problems, it is futile to expect that fundamental progress 

 in our comprehension of the mechanism of locomotion 

 of the myxobacteria, for example, could be made as the 

 result of team work at the present time. 



Wood's discovery of the antagonistic effect of para- 

 aminobenzoic acid on the inhibition of bacterial growth 

 by sulfanilamide led to a new concept of the mode of action 

 of growth inhibitors, and this opened up the fruitful field 

 of investigations on antimetabolites. Similarly, Fleming's 

 chance observation on the absence of bacterial colonies in 

 the vicinity of a mold contaminant, coupled with the 

 demonstration some years later, by Dubos and by Hooger- 

 heide, that special substances can be isolated from cultures 

 of spore-forming bacteria that prevent the development of 

 other microorganisms, constituted another break-through; 

 it could be systematically exploited by teams of specialists 

 and marked the beginning of the antibiotics industry. The 

 spectacular results are evident to everyone who has some 

 knowledge of present-day medical practice. 



It is important to remember that these developments 

 have their origin in observations with mixed rather than 

 pure cultures, and hence involve an accidental or deliber- 

 ate deviation from what had become standard microbio- 

 logical practice. This brings into focus the significance of 

 studies of the behavior of microorganisms under conditions 

 where competition among various types is not a priori 

 excluded. During the last thirty years Winogradsky re- 

 peatedly insisted on the need for studying the role of 



