212 moderator: s. hestrin 



cells, however, the amount of shrinking on drying is of the 

 same order as the shrinking in a drying piece of meat. This 

 would explain the sensitivity of non-frozen vegetative cells to 

 drying, and serves as still another example of the importance to 

 be ascribed to structure conservation for the preservation of 

 viability during drying. 



(II) Resistance and Cryptobiosis 



Moderator: The endogenous class of cryptobiosis might 

 perhaps be defined as a hypometabolic state whose sustained 

 duration involves an endogenous regulatory mechanism. Would 

 anybody like now to demolish this definition? 



Koller : I have no intention of tearing it down without some 

 previous study. But you should note that a state of dormancy 

 is one that enables an organism to pass through an unfavourable 

 environment without drying. It seems to me that the important 

 criterion is the resistance to external conditions. It is this which 

 determines whether a state is dormant or not. 



Lees: I am afraid that this would not do for insects. If you 

 take, say, resistance to cold, it is true that dormant insects are 

 often resistant, but other insects, without a diapause, are some- 

 times equally cold-hardy. 



Halvorson: As for micro-organisms, cells in a dormant state 

 have an enhanced resistance to their environment. In bacterial 

 spores we use loss of heat resistance as a means of determining 

 whether dormancy has been broken. 



Samish : In the cells of a bud going into rest the protoplasm 

 becomes more viscous and less transparent whilst the proportion 

 of bound water is increased. Bennett in Berkeley found a 

 correlation between the depth of rest and the amount of bound 

 water. With the breaking of rest the protoplasm becomes more 

 liquid and the bound water percentage is decreased. 



Halvorson : I was a member of the faculty of the University 

 of Minnesota when Dr. Gortner first introduced the term: bound 

 water. I then strongly disagreed with him, and I still think it is 



