SB 2.10.18

mukhatas tālu nirbhinnaṁ
 jihvā tatropajāyate
tato nānā-raso jajñe
 jihvayā yo ’dhigamyate
Synonyms: 
mukhataḥ — from the mouth; tālu — the palate; nirbhinnam — being generated; jihvā — the tongue; tatra — thereupon; upajāyate — becomes manifested; tataḥ — thereupon; nānā-rasaḥ — various tastes; jajñe — became manifested; jihvayā — by the tongue; yaḥ — which; adhigamyate — become relished.
Translation: 
From the mouth the palate became manifested, and thereupon the tongue was also generated. After this all the different tastes came into existence so that the tongue can relish them.
Purport: 

This gradual process of evolution suggests the explanation of the controlling deities (adhidaiva) because Varuṇa is the controlling deity for all relishable juices. Therefore the mouth becomes the resting place for the tongue, which tastes all the different juices, of which the controlling deity is Varuṇa. This suggests, therefore, that Varuṇa was also generated along with the development of the tongue. The tongue and the palate, being instrumental, are adhibhūtam, or forms of matter, but the functioning deity, who is a living entity, is adhidaiva, whereas the person undergoing the function is adhyātma. Thus the three categories are also explained as to their birth after the opening of the mouth of the virāṭ-puruṣa. The four principles mentioned in this verse serve to explain the three main principles, namely the adhyātma, adhidaiva and adhibhutam, as explained before.