42 L. LEON CAMPBELL, JR. 



mancy. This meant, therefore, that germination in the traditional sense re- 

 ferred to the morphological changes coincident with the breaking of the 

 spore wall, perhaps with the protrusion of a germ tube; the excystment of 

 certain animals would also fit in this category. Therefore, the stages be- 

 tween the rupture of dormancy by whatever means and the emerging of the 

 vegetative mycelium, or vegetative animal, were all lumped together in the 

 process called germination. Subsequent to this, refinements in physiological 

 and biochemical techniques made it possible to study the transition from the 

 dormant organism to the germinated one. Due to these refinements transi- 

 tion stages appeared, one of which Dr. Church and I have called the acti- 

 vated stage. 



To me the sequence of stages as recently worked out by Church and Hal- 

 vorson coincides very nicely with some of the observations in fungus sys- 

 tems with which I have worked. For example, in the dormant cells of some 

 fungi one has a system where there are qualitative differences in their me- 

 tabolism as compared with the vegetative organism. Immediately upon the 

 application of a stimulus that will break dormancy, metabolic changes en- 

 sue before recognizable morphological ones appear, so that the traditional 

 usage of the term "germinated" cannot be applied. Therefore, there are 

 three stages which I see in general: There is the dormant cell; then there is 

 the in-between stage which is not dormant and is not germinated, but which 

 I prefer to call the activated stage, followed, of course, by the germinated 

 cell. I should like to refer to the work of Church and Halvorson again, for 

 I think that there is a strict parallel with the situation discussed for fungus 

 spores. In the case of the spores with which these authors worked, if the 

 heat-shocked cell is studied before it is confronted with what I would call 

 an activating agent like sugar, many enzymatic changes occur. Here, then, 

 is a cell in the never-never stage between the dormant one which shows re- 

 stricted enzymatic activities and the germinating cell which shows the change 

 in heat resistance; it is, therefore, a cell that is heat resistant but activated 

 in the sense of metabolic activtity. Its heat resistance makes it a hybrid be- 

 tween the dormant and vegetative condition. For these reasons I suggest 

 that consideration be given the concept that the stage intermediate between 

 the dormant and germinating one be called the activated stage. 



ROBINOW: I should like to make two comments. In experiments on the 

 sensitivity of spores of B. cereus to X-rays, carried out with the late Douglas 

 Lea and repeated over here, it was found that exposure of 1 and IVij million 

 roentgen units, although it suppressed outgrowth of viable bacilli, did not 

 prevent the spores from losing their refractility and becoming stainable 

 when transferred to a nutrient medium. I wonder whether others have made 

 similar observations and, if so, whether the interval elapsing between the 



