Corona and Sphere - Puzzle

Greetings all,
                     Following some very interesting discussions offlist 
with Boris Petkovic, I and he have a problem we would like to throw 
into the arena for comment and possibly some answers.  I can 
formulate the problem like this:

       I have a sphere of a chosen diameter. It is connected to the top 
of a TC. At some voltage, the sphere will issue a visible streamer.  
We know that air streamers do not lower the Q of a system to a high 
degree. The relatively high Q of system doing this has been 
measured by myself and others and manifests itself as a continuing 
series of beats which are visible on an e-field oscilloscope trace of 
the secondary.  

         The question:  Why does a single rooted streamer or just a 
few streamers appear when the breakdown voltage of the sphere 
has clearly been reached?  Why not all around?

     Something to consider: I have operated a coil such that the 
voltage it reached was not sufficient to promote a visible streamer 
but if the sphere was viewed in *very* dark conditions, the terminal 
was indeed surrounded by a ball of wispy streamers issuing in all 

     Does anyone have any comment on this? Is there any *good* 
reason why, when terminal voltage has reached such a level as to 
allow the issuing of a single bright streamer more are not issued?

      The problem appears simple on the surface but perhaps not so 
simple if one delves deeply enough into what is happening.

      I've tried to formulate the problem as concisely as I can but 
perhaps Boris might like to elaborate if he feels I have missed 
something. This is written in some haste as I am about to go away. I 
look forward to reading the answers when I return.