10 Perspecfives in Microbiology 



tactic movements of microorganisms might help in analyz- 

 ing certain aspects of stimulus conduction by nerves. 



In connection with microbial locomotion, I cannot re- 

 frain from mentioning the problem posed by the existence 

 of Salmonella strains with nonfunctional flagella; the still 

 unsolved mechanisms responsible for the movements of 

 microorganisms devoid of flagella, like the desmids, blue- 

 green algae, myxobacteria, and Labyrinthula; and the 

 phenomena known as elasticotaxis and elasticotropism, en- 

 countered in organisms with gliding motility and in 

 Kurthia zopfii, representing responses to gradients in stress 

 of the substrate, similar to that exhibited by growing nerve 

 cells. 



It is obviously impossible to predict where future studies 

 of such phenomena may lead. But I believe that in the 

 end science would benefit if the tentative and often un- 

 rewarding probings into the behavior of microorganisms 

 on a level now beyond the scope of biochemical and bio- 

 physical experimentation were not merely tolerated but 

 encouraged. The tendency to look down on the efforts of 

 microbiologists who do not follow the current trends, and 

 to brand such studies as rather primitive dabblings in the 

 natural history of microorganisms, seems to me short- 

 sighted. It would be well to realize that the important 

 developments in microbial biochemistry and genetics, for 

 example, have resulted from the emergence of novel con- 

 cepts that may be compared to a "break-through" in a 

 deadlocked military front. The successful exploitation of 

 such concepts is accomplished by the concerted efforts of 

 many specialists, and the opportunity for doing so is gen- 

 erally recognized at an early stage. One cannot anticipate, 

 however, when or where a new break-through may take 

 place. It usually is preceded by the accumulation of numer- 

 ous seemingly trivial observations which gradually arrange 

 themselves, in the mind of an alert scientist long preoccu- 



