  We demonstrate that the space-time statistics of the birth of turbulent spots
in boundary layers can be reconstructed qualitatively from the average behavior
of macroscopic measures in the transition zone. The conclusion in \cite{vg04}
that there exists a connection between the patterns in laminar instability and
the birth of turbulent spots is strengthened. We examine why the relationship
between instability and transition to turbulence is manifest in some cases and
appears to be totally absent in others. Novel cellular automaton type
simulations of the transition zone are conducted, and the pattern of spot birth
is obtained from secondary instability analysis. The validity of the hypothesis
of concentrated breakdown, according to which most turbulent spots originate at
a particular streamwise location, is assessed. The predictions made lend
themselves to straightforward experimental verification.
