Fig. 78—*Liver cells* where is stored the glycogen. _C._ Capillaries.


[Fig. 79]


Fig. 79—*Stored-up fat.* The figure shows four connective tissue cells
containing small particles of fat. 1. Nucleus. 2. Protoplasm. 3. Fat. 4.
Connective tissue fibers.


2. _The fat_ is stored for the most part in the connective tissue. Certain
of the connective tissue cells have the property of taking fat from the
blood and of depositing it within their inclosing membranes (Fig. 79).
When this is done to excess, and the cells become filled with fat, they
form the so-called _adipose tissue_. Most of this tissue is found under
the skin, between the muscles, and among the organs occupying the
abdominal cavity. If one readily takes on fat, it may also collect in the
connective tissue around the heart. The stored-up fat is redissolved as
needed, and enters the blood, where it again becomes available to the
active cells.

3. _The proteids_ form a part of all the tissues, and for this reason are
stored in larger quantities than any of the other food substances. The
large amount of proteid found in the blood may also be looked upon as
storage material. The proteids in the various tissues are spoken of as
_tissue proteids_, and those in the blood as _circulating proteids_. The
proteids of the tissues serve the double purpose of forming a working part