THE BACTERIAL ENDOSPORE 63 



Hestrin: Does addition of dipicolinic acid to the non-heat- 

 resistant cells confer heat stability? 



Halvorson: Cultures to which ethyl oxamate has been 

 added, and which normally should yield heat-sensitive spores, 

 will produce heat-resistant spores on the addition of dipicolinic 

 acid. 



