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Groups of Two Mutes in Middle Indo-Aryan
THOUGH it is natural to suppose that the assimilation of various consonant-groups was a slow process, showing different stages in its growth, before it reached its maximum extent and scope, which it did in the period of Classical Prākrits, it is not always possible to note all such intermediate steps in the history of the MIA. languages themselves. Like all linguistic changes, assimilation has its own period of growth, and it cannot be rigidly confined to any one given stage which may be conveniently postulated in the growth of a family of languages like the Indo-Aryan. However careful we may become in choosing a number of features as marking the MIA. stage as distinguished from the OIA., it is bound to result into some kind of arbitrariness, and these distinctions are to be accepted more for the sake of convenience than for their strict accuracy.
Usually, assimilation of all kinds of consonant-groups along with a few other changes has been regarded as the hall-mark of the MIA. stage, and this is found convenient in readily distinguishing the MIA. dialects from the OIA. But this cannot be taken in a very strict sense. The process of assimilation has an earlier beginning which goes beyond the limits of the MIA. and reaches back into the OIA. On the other hand this process has not attained its completion even by the end of the MIA. period. Even if we try to define more accurately the distinguishing feature of the MIA. to consist in a complete more than a partial assimilation, the historical limits of even this restricted phenomenon do not coincide with the accepted limits of the MIA. dialects.
Probably the nearest approach to such a demarcating feature can be found in the process of assimilation of two plosives, which is almost universally operative in all the stages of the MIA. Even then the beginnings of this change are to be found in the OIA. period. Classical Sanskrit itself shows various traces of this type of assimilation. When two stops come into