अचश् च

This is a paribhasha sutra, and declares the object to which the terms 'short, 'long' and 'prolated' are to be applied. When in this book 'short' 'long' or 'prolated' are taught by using the words hrasva, dirgha or pluta, they must be understood to apply to vowels. As will be found in the sutra (1. 2. 47) \\[1\\] \there is the substitution of hrasva or short in the neuter gender of the crude-form.\ The word 'vowel' must be inserted in this sutra to complete the sense. That is:- the hrasva is substituted for the final vowel of the crude-form. As रै अतिरि, नौ अतिनु, गा उपगु.

The substitution must take the place of vowel and not consonant. As सुवाग् ब्राह्मणकुलम्.

Similarly sutra 7.4.25 \\[2\\] teaches \There is the substitution of dirgha or 'long vowel' before all affixes beginning with the letter य्, except krit and Sarvadhatuka affixes.\ Here also the word 'vowel' must be read into the sutra which will then be \of an inflective base ending in a vowel, the long vowel shall be the substitute &c.\ As चि + यङ् + त = चीयते 'it is collected'; श्रु + य + त = श्रूयते 'it is heard.' Why do we say \in the place of vowels only\? The substitution must take place in the room of a vowel and not of a consonant. As भिद् + य + ते = भिद्यते 'it is divided,' छिद्यते 'it is pierced.'

So also in the case of pluta substitution. Thus rules 8.2.82 and 8.2.84 \\[3\\], declare that in calling from a distance, pluta is substituted for the टि portion of the word in the vocative. (The word टि is defined in 1.1.64). Here also the phrase 'of the vowel' must be read into the sutra to complete the sense. The sutra will then read:- \Pluta is substituted in the place of the vowel of the टि &c.\ Thus देवदत्त३, O Devadatta! यज्ञदत्त३ O Yajnadatta !

Why do we say \in the place of vowels only\? The substitution must be in the place of the vowel of the टि and not of the consonant. As अग्निचि३त्, सोमसु३त्. Here the syllables इत् and उत् are टि, and the vowels इ and उ have been prolated and not the consonant त्.

The substitution must be enunciated as such by using the terms, hrasva, dirgha, and pluta. Therefore it is not so here; द्यौः, पन्थाः, सः, द्युभ्याम्, द्युभिः See (I. I. 4).

## Footnotes
- [1] - हृस्वो नपुंसके प्रातिपदिकस्य ॥
- [2] - अकृत्सार्वधातुकयोर्दीर्घः ॥
- [3] - वाक्यस्यटेः प्लुत उदात्तः ॥ दूराद्धूतेच ॥,