  In this brief note I address the question not frequently asked, namely, why
did it take two decades between Einstein's first proposal of photons and
derivation of the full Planck formula from first principles of Statistical
Mechanics, albeit with a fundamental new approach to counting of states.
Secondly, why did it fall to an independent inquirer, S. N. Bose, in far away
Dacca to arrive at the correct derivation of this formula, arguably a most
crucial one of the first half of the twentieth century? Reasonable hypotheses
are proposed for answers to both. I also argue that the timing of Bose's
communication to Einstein played a crucial role in Einstein's approval of de
Broglie's thesis and hence the emergence of the definitive version of quantum
mechanics in the late 1920's.
