ar) are carried in the portal blood stream to the
liver, where they are actually stored away in the form of glycogen
which, in a most intelligent manner, is dealt out to the body from
hour to hour as it is needed for fuel. If all the sugar, after a
hearty meal, were poured into the circulation at once, the blood
stream would be overwhelmed and the kidneys would be forced to
excrete it in the urine. This unnecessary waste is avoided by the
liver's storing sugar after each meal and dealing it out to the body
as required.

Likewise, the proteins also pass through the liver on their way to the
body. Just what action the liver exerts upon proteins is not wholly
known at the present writing. The digested fats are absorbed at once
by the lacteals, the beginning of the intestinal lymphatic system, by
which they are carried to the large veins at the root of the neck and
there emptied into the blood stream. We have now traced our various
food elements through the processes of digestion and absorption in the
alimentary tract, some going through the liver, and others through the
lymphatic system, until they circulate in the blood stream itself.

It is from these food substances, circulating in the blood stream,
that the various cells of the body must assimilate into themselves
such portions as they require for purposes of heat and energy and for
the repair of their cell substance. This specialized work of cell
assimilation converts the dissolved watery food in the blood into
solid tissues, exactly reversing the process of digestion.

With a most profound intelligence, each of these body cells and
tissues, bone and nerve fiber, muscle and organ, selects from the
blood stream just its supply or portion of the food elements requisite
to its upbuilding and maintenance. The mysteries of assimilation are
effected by means of chemical substances called "enzymes," similar to
those found in the digestive organs, but acting in an entirely
different manner, in that they build up solids out of liquids instead
of converting solids into liquids.

ELIMINATION OF BODY WASTES

Metabolism consists of a twofold role--an upbuilding and a tearing
down process. After the food is all digested, absorbed, and
assimilated, having become a part of the bodily organ, bone, muscle,
and nerve fiber, then begins the work of tearing it down--of
liberating its heat and energy--to be followed by its elimination
from the body through the sweat glands, urinife