common language in India

[DR.S.KALYANARAMAN]

hi,
I was asked a question: "How is it a common language
did not evolve in India?" I hope I am not raising a
hornet's nest of historical linguistic problems.
Jules Bloch answered some in his magnificent
Formation of the Marathi Language and Burrow in
his Sanskrit Language. Are there any works which
address the philological question in the context of
Pali and Prakrits? Regards. kalyanaraman