clothe), it is, on account of the equivalence and interchangeability of dhv and ddhv (232), impossible to say whether the s in omitted or converted into d.
a. Final radical s is very rare; RV. (twice, both 2d pers. sing.) treats ághas from √ghas in the same manner as any ordinary word ending in as.
b. For certain cases of irregular loss of the s of a root or tense-stem, see 233 b–e.
167. In a few very rare cases, final radical s before s is changed to t (perhaps by dissimilation): they are, from √vas dwell (also sporadically from vas shine, ÇB., and vas clothe, Har.), the future vatsyā́mi and aorist ávātsam; from √ghas, the desiderative stem jíghatsa.
a. For t as apparent ending of the 3d sing. in s-verbs, see 555 a.
168. According to the grammarians, the final s of certain other roots, used as noun-stems, becomes t at the end of the word, and before bh and su: thus, dhvat, dhvadbhis, sradbhyas, sratsu. But genuine examples of such change are not quotable.
a. Sporadic cases of a like convention are found in the Veda: namely, mādbhís and mādbhyás from mā́s: uṣádbhis from uṣás; svátavadbhyas from svátavas; svávadbhis etc. (not quotable) from svávas. But the actuality of the conversion here is open to grave doubt; it rather seems the substitution of a t-stem for a s-stem. The same is true of the change of vāṅs to vat in the declension of perfect participles (458). The stem anaḍvah (404), from anas-vah, is anomalous and isolated.
b. In the compounds ducchúnā (dus-çunā) and párucchepa (parus-çepa), the final s of the first member is treated as if a t (203).
169. As the final consonant of derivative stems and of inflected forms, both of declension and of conjugation, s is extremely frequent; and its changes form a subject of first-rate importance in Sanskrit euphony. The r, on the other hand, is quite rare.
a. The r is found as original final in certain case-forms of stems in ṛ or ar (369 ff.); in root-stems in ir and ur from roots in ṛ (383 b); in a small number of other stems, as svàr, áhar and ū́dhar (beside áhan and ū́dhan: 430), dvā́r or dur, and the Vedic vádhar, uṣar-, vasar-, vanar-, çrutar-, sapar-, sabar-, athar- (cf. 176 c); in a few particles, as antár, prātár, púnar; and in the numeral catúr (482 g).
b. The euphonic treatment of s and r yielding precisely the same result after all vowels except a and ā, there are certain forms with regard to which it is uncertain whether they end in s or r, and opinions differ respecting them. Such are ur (or us) of the gen.-abl. sing. of ṛ-stems (371 c), and us (or ur) of the 3d plur. of verbs (550 c).
