Bhagavad Gita 13.6महाभूतान्यहङ्कारो बुद्धिरव्यक्तमेव च।इन्द्रियाणि दशैकं च पञ्च चेन्द्रियगोचराः ॥

The field and its modifications are described in this verse. The twentyfour principles of the Sankhya school of philosophy are mentioned here.Great elements Earth, water, fire, air and ether are so called because they pervade all modifications of matter. The elements here referred to are the subtle, not the gross ones.Egoism is the cause of the great elements. It is the selfarrogating principle. Intellect is the cause of egoism. The function of the intellect is determination. Buddhi is the faculty of determination. The cause of the intellect is the Unmanifested (which is the undifferentiated energy of the Lord). (Cf.VII.14 Daivi hyesha gunamayi mama maya duratyaya -- This divine illusion of Mine, caused by the alities, is difficult to cross over.) The above Nature is divided eightfold (Cf.VII.4).The ten senses are the five organs of knowledge (ears, skin, eyes, tongue and nose), so called because they enable the mind to get knowledge of the external world, and the five organs of action (hands, feet, mouth, anus and the generative organ), so called because they perform actions.The one This is the mind. This is the eleventh sense whose function is thinking and doubting (Sankalpa and Vikalpa).The five objects of the senses are sound, touch, form (colour), taste and smell