Go through
Counter-intuitive that growth is irrelevant except for time.
Solution allows for time varying growth rate
Obvious extension to explicitly include limitation
EXPLAIN LIMITATION
   - if less near exponential
   - if greater decay
Regimes
Confirms earlier model for beta<2.5
For beta>2.5
   - biology now important
   - width larger than for exponential growth
     - counter-intuitive
All nice theory, but what use?