Of them that were unable, through feat of Rama, lo perform the duties ordained for their order, the progeny became Vrishalas owing to their inability to find Brahmanas.
तेषां स्वविहितं कर्म तद्भयान्नानुतिष्ठताम्। प्रजा वृषलता प्राप्ता ब्राह्मणानामदर्शनात्॥