and complicated by two circumstances: their reversion to a guttural form (or the appearance of the unaltered guttural instead of them: 43); and the different treatment of j and h according as they represent one or another degree of alteration — the one tending, like c, more to the guttural reversion, the other showing, like ç, a more sibilant and lingual character.
120. The lingual sibilant s, also of derivative character (from dental s), shows as radical final peculiar and problematic phenomena of combination.
121. Extension and abbreviation of consonant-groups. The native grammarians allow or require certain extensions, by duplication or insertion, of groups of consonants. And, on the other hand, abbreviation of certain other groups is allowed, and found often practised in the manuscripts.
122. Permitted Finals. The permitted occurrence of consonants at the end of a word is quite narrowly restricted. In general, only one consonant is allowed after the last vowel; and that must be neither the aspiration, nor a sibilant, nor a semivowel (save rarely ल् l), nor an aspirate mute, nor a sonant mute if not nasal, nor a palatal.
123. Increment and Decrement. Besides these more or less regular changes accompanying the combination of the parts that make up words, there is another class of a different character, not consisting in the mutual adaptations of the parts, but in strengthening or weakening changes of the parts themselves.
124. It is impossible to carry through a perfectly systematic arrangement of the detailed rules of euphonic combination, because the different varieties of euphonic change more or less overlap and intersect one another. The order observed below will be as follows:
1. Rules of vowel combination, for the avoidance of hiatus.
2. Rules as to permitted finals (since these underlie the further treatment of final consonants in external combination).
3. Rules for loss of aspiration of an aspirate mute.
4. Rules of surd and sonant assimilation, including those for final s and r.
