PURE CULTURES. 



17 



plate 4 than from the same plant a week later (fig. 10). One wonld also be more 

 certain of pnre cnltures by plating from the interior of the plant at A, I!, or C, 

 rather than at X or Y. 



The jndgment of experienced bacteriologists as to the pathogenic natnre of 



F.g. 10.* 



an organism may to a certain extent be accepted in absence of full proof, but 

 only for the time being. Nothing is absolutely certain which has not been experi- 

 mentalh' demonstrated. 



*FiG 10. Datura inetelloides, inoculated by needle-pricks witli Bacterium solaiiaccariiiii. Tlie 



same as plate 4, but six daj-s later, i. c, on July 28. 



