262 GENERAL MICROBIOLOGY 



If all of these operations are successful Koch's postu- 

 lates have been fulfilled. (See reference, W. J. MacNeal, 

 Exercise 1, Animal Diseases and Immunity.) 



15. What do you conclude as to the physiological 

 efficiency of the culture of Ps. radicicola used? 



16. What several factors might be responsible for a 

 failure of infection? Explain. 



Why are inoculated seeds kept from direct sunlight? 

 What may be the advantage of seed inoculation? How 



FIG. 57. Ps. radicicola, Polar flagella, x!500. Twenty-five day old 

 culture from sweet pea. (B. Barlow). 



do different methods of seed inoculation compare as to 

 advantages and disadvantages? 



17. Give your results in detail and draw conclusions. 

 Point out any possible practical applications. 



REFERENCES 



MARSHALL: Microbiology, pp. 273-283. 



LAFAR: Technical Mycology, Vol. I, pp. 259-271. 



LOHNIS: Laboratory Methods in Agricultural Bacteriology, pp. 



111-113. 

 LIPMAN and BROWN; Laboratory Guide in Soil Bacteriology, pp. 



56-59, 76-77, 



