216 moderator: s. hestrin 



Keynan: Does not a change of this sort in fact also occur in 

 insects? 



Mayer: From Dr. Lees' comments it seems that as far as 

 insects are concerned the verdict should be a 'not proven' 

 rather than a 'nonexistant'. It seems to me that by the use of 

 the Britton-Chance spectrophotometer technique we could learn 

 whether or not there is a change in cytochrome Z?5 and cyto- 

 chrome c in diapause, and thus show whether or not the 

 cytochrome system is operative in this stage. 



Lees: A dramatic fall in cytochrome c concentration has in 

 fact been demonstrated by Shappirio using low temperature 

 spectroscopy. 



Poljakoff-Mayber : We cannot be sure that there is no 

 previously accumulated energy-store in the form of ATP. This 

 store could be used during dormancy. After all, in the latent 

 state of metabolism there may not be much need for energy. 



Halvorson Jr.: We do not know the ATP/ADP ratios in 

 the spore. It would be worthwhile indeed to measure this. 

 There are only FitzJames' observations on this subject, on a 

 correlation between germination and polyphosphate degrada- 

 tion. 



Mayer: The polyphosphate, phytin, might be such an energy 

 store in a dormant seed. 



Moderator: The difficulties of the approach to this problem 

 are formidable. I would not wish to sound pessimistic, but 

 please realize that whereas in the bacterial system we know what 

 cell is dormant, and can test that cell, in insects and plants there 

 appears to be as yet no accurate location of dormancy, and no 

 means therefore of differentially examining the critical locus. 



Samish : Well, in buds, some think that the scales form a wall 

 which prevents the entry of oxygen and thus induces dormancy, 

 but others hold the opposite view, that it is the dormancy which 

 induces the formation of an impermeable protoplasmic mem- 

 brane. A group of Russian workers has correlated entry into 

 dormancy with constriction of the protoplast and resultant 

 scission of the plasmodesma. They have also found that when 



