THE BACTERIAL ENDOSPORE 35 



except for the presence of some metal ions which inhibited the 

 process. Upon the addition of versene, the toxic metal ions were 

 removed and germination proceeded. Dr. Riemann-^ (personal 

 communication) in Denmark, working in OrdaFs laboratory, 

 has made an even more interesting observation. He has been 

 able to germinate most spores with an equimolecular mixture of 

 calcium and dipicolinic acid. He observed this while making 

 some studies on the effect of chelating agents on germination. 

 Knowing that dipicolinic acid is a fairly effective chelating 

 agent, he tried to use this in place of versene and found it would 

 bring about germination only in the presence of calcium ions. 

 The most rapid change was obtained when he had an equi- 

 molecular mixture of the two. 



It is apparent from the above that the discoveries made by 

 Hills can be looked upon as forerunners of many important 

 advances in our knowledge of the germination of spores. 



The second observation which I mentioned above, namely, 

 the demonstration of active enzymes in intact spores, was m.ade 

 in connection with some of our studies on germination. We 

 observed, as others have, that when spores germinate in the 

 presence of L-alanine and adenosine or, as a matter of fact, with 

 any of the other combinations of germ.ination ingredients, not 

 all of the spores in a suspension will do so. From 90 to 98 % 

 germinate, but the balance remains heat-stable and unchanged. 

 The question naturally arises, why do these remaining spores 

 fail to behave like the rest? Is it because they are different or 

 because something has happened to the menstruum? To answer 

 this question we examined the solution in which the spores had 

 germinated to see whether the L-alanine or the adenosine, or 

 both, had been used up. We found there appeared to be no 

 change in the concentration of either, during the germination 

 process. If either of the chemicals had been used, the amount 

 was too small to be detected by our methods of analysis. It 

 appeared nothing had happened to the solution; one would be 

 tempted to assume, therefore, that the spores v/hich failed to 

 germinate might be different from the remaining bulk that 



References p. 59 



