Astanga Hrudaya
अन्नस्य पक्ता सर्वेषां पक्तॄणामधिको मतः। तन्मूलास्ते हि तद्वृद्धिक्षयवृद्धिक्षयात्मकाः॥७१॥
Among all these digestive agencies, that which cooks the food (i.e jatharagni, kosthagni) is great (in strength), it is the root for them (bhutagni and dhatvagni); its increase and decrease make for their increase and decrease respectively;
english translation