The feminine is not changed into masculine when it is formed by such a taddhita affix which causes the vṛddhi of the first syllable with exception however of taddhita-substitute meaning 'coloured therewith' and 'made thereof'.,
Thus स्रौघ्नीभार्यः, माथुरीभार्यः, स्रौघ्नीपाशा, माथुरीपाशा, स्रौघ्नीयते, माथुरीयते, स्रौघ्नीमानिनी and माथुरीमानिनी ॥
Why do we says 'which causes Vriddhi'? Observe मध्यमभार्यः (मध्ये भवा = मध्यमा formed by the affix म 4.3.8 which does not cause Vriddhi). Why do we say 'of a Taddhita'? Observe काण्डलावभार्यः (काण्डं लुनाति = काण्डलावी with अण् (कर्मण्यण्) and ङीप्). Why do we say when not meaning 'colored there with' or 'made thereof'? Observe कषायेण रक्ता = काषायी, काषायी वृहतिका यस्य = काषायवृहतिकः, लोहस्य विकारोलौही लौही ईषा यस्य स्थस्य = लोहेषः 4.3.134. The word वृद्धिनिमित्तस्य should be explained as a Bahuvrihi, and not a Tatpurusha, i. e. a taddhita affix, in which there is an element like ण् or ञ् or क् &c which causes Vriddhi. Therefore this exception does not apply to तावद्भार्यः यावद्भार्यः (तावती भार्या यस्य &c). Here the affix वतुप् 5.2.39 added to तद् does not cause Vriddhi by its own force, but by 6.3.91.,