in carrying out urine and
faeces. That single breath which operates in these three, is called Udana
by those that are conversant with science. That breath which operates,
residing in all the joints of men's bodies, is called Vyana. There is
heat in the bodies of living creatures which is circulated all over the
system by the breath Samana. Residing thus in the body, that breath
operates upon the different kinds of watery and other elementary
substances and all bad humours. That heat, residing between Apana and
Prana, in the region of the navel, operates, with the aid of those two
breaths, in digesting all food that is taken by a living creature. There
is a duct beginning from the mouth down to the anal canal. Its extremity
is called the anus. From this main duct numerous subsidiary ones branch
out in the bodies of all living creatures.[558] In consequence of the
rush of the several breaths named above (through these ducts), those
breaths mingle together. The heat (that dwells in Prana) is called
Ushman. It is this heat that causes digestion in all creatures possessed
of bodies. The breath called Prana, the bearer of a current of heat,
descends (from the head) downwards to the extremity of the anal canal and
thence is sent upwards once more. Coming back to its seat in the head, it
once more sends down the heat it bears. Below the navel is the region of
digested matter. Above it is that for the food which is taken. In the
navel are all the forces of life that sustain the body. Urged by the ten
kinds of breaths having Prana for their first, the ducts (already
mentioned), branching out from the heart, convey the liquid juices that
food yields, upwards, downwards, and in transverse directions.[559] The
main duct leading from the mouth to the anus is the path by which yogins,
vanquishers of fatigue, of perfect equanimity in joy and sorrow, and
possessed of great patience, succeed in attaining to Brahma by holding
the soul within the brain.[560] Even thus is heat planted in the breaths
called Prana and Apana and others, of all embodied creatures. That heat
is always burning there like a fire placed in any (visible) vessel.'"'"

SECTION CLXXXVI

"'"Bharadwaja said, 'If it is the wind that keeps us alive, if it is the
wind that causes us to move and exert, if it is the wind that causes us
to breathe and to speak, then it seems that life is worth little. If the
animal heat (that digests all food) be of the nature of fire, an