PHONOLOGY IOI same general tendency was at work which later resulted in the assimilation of all consonant groups. With few exceptions (e.g. nom. sg. urk from tirj- * vitality ') not more than one con- sonant may stand at the end of a word, however many were there to begin with. This had serious results in some aspects of the morphology, and led to some grammatical innovations. Thus the terminations are lost in the case of the second and third persons singular of the root and s-aorists, and the s of the s-aorist suffers the same fate in these persons when preceded by a consonant, so that the formations lose their grammatical clarity. On account of this the root aorist comes to be abandoned in Classical Sanskrit except in the case of roots in long d t and new extended formations are provided in the case of the s-aorist (anaistt for dnais). The weakest of the final consonants was s. In final position this is weakened to the breathing h ( visarga ). In sandhi the same change occurs before k, p and the sibilants. Preceded by d it is elided before voiced consonants and vowels. The same thing happens when it is preceded by a, but here the -as is in most contexts replaced- by o. In the non-Sanskritic dialects of Old Indo-Aryan there was an alternative development of - as to -e. An example of this is found even in the Rgveda (sure duhitd ‘ daughter of the sun ') ; later it is a characteristic of the Eastern (Magadhi) Prakrits, and examples are also found in some of the Kharosfhi inscriptions of the North-West. These developments of final -as began in the Indo-Iranian period, and in Avestan likewise -6 is the common representative of final -as, beside which there is a dialectal variant -5 corresponding to the -e of Magadhi, etc. Final s is preserved only before t , th, while before c, ch it exists in the modified form s'. When preceded by i, u, s became originally s (§ 9 ) which would normally become Sanskrit s. In place of this s, before voiced consonants and vowels r is substituted. The intermed- iate stage was presumably 2 and in this case there is complete difference of treatment of a phoneme at the end of a word from iis treatment internally. This external sandhi was extended to the sandhi of compounds (durdama-, etc.) but old forms like diildbha - (dud°-<.duzd°-) and kdrulatl show that this is not original but analogical. Likewise the sandhi of neuter s- stems in declension (havirbhis, havihsu ; . manobhis , tnanahsu) is in imitation of the external sandhi.
