242. In a number of roots

In a number of roots (about a dozen quotable ones) ending in ṛ (for more original ar), the ṛ changes both with ar, and more irregularly, in a part of the forms, with ir—or also with ur (especially after a labial, in pṛ, mṛ, vṛ, sporadically in others): which ir and ur, again, are liable to prolongation into īr and ūr. Thus, for example, from tṛ (or tar), we have tarati, titarti, tatāra, atāriṣam, by regular processes; but also tirati, tīryati, tīrtvā, -tīrya, tīrṇa, and even (V.) turyāma, tuturyāt, tarturāṇa. The treatment of such roots has to be described in speaking of each formation.

a. For the purpose of artificially indicating this peculiarity of treatment, such roots are by the Hindu grammarians written with long ṝ, or with both r and ṝ: no ṝ actually appears anywhere among their forms.

b. The (quotable) ṝ-roots are 2 kṛ strew, 1 gṛ sing, 2 gṛ swallow, 1 jṛ wear out, tṛ, 1 çṛ crush.

c. The (quotable) ṛ and ṝ-roots are ṛ, 1 dṛ pierce, 1 pṛ fill, 1 mṛ die, 2 vṛ choose, stṛ , hvṛ.

d. Forms analogous with these are sometimes made also from other roots: thus, cīrṇa, cīrtvā, carcūryá, from √car; spūrdhán and spūrdháse from √spṛdh.