The body (the total body and the individual body are of the same composition) may figuratively be called “the original tree.” From this tree, which fully depends on the ground of material nature, come two kinds of fruit—the enjoyment of happiness and the suffering of distress. The cause of the tree, forming its three roots, is association with the three modes of material nature—goodness, passion and ignorance. The fruits of bodily happiness have four tastes—religiosity, economic development, sense gratification and liberation—which are experienced through five senses for acquiring knowledge in the midst of six circumstances: lamentation, illusion, old age, death, hunger and thirst. The seven layers of bark covering the tree are skin, blood, muscle, fat, bone, marrow and semen, and the eight branches of the tree are the five gross and three subtle elements—earth, water, fire, air, ether, mind, intelligence and false ego. The tree of the body has nine hollows—the eyes, the ears, the nostrils, the mouth, the rectum and the genitals—and ten leaves, the ten airs passing through the body. In this tree of the body there are two birds: one is the individual soul, and the other is the Supersoul.
– Srimad Bhagavatam