Astanga Hrudaya
शोणितप्रभृतीनां च धातूनामुत्तरोत्तरम्। मांसाद्गरीयो वृषणमेढ्रवृक्कयकृद्गुदम् ॥७१॥
The tissues of the animals such as blood and others are hard to digest in their successive order; testicles, penis, kidneys, liver and rectum are hard to digest than the flesh.
english translation
zoNitaprabhRtInAM ca dhAtUnAmuttarottaram। mAMsAdgarIyo vRSaNameDhravRkkayakRdgudam ॥71॥
hk transliteration by Sanscript