This modification of the reparative process can be best studied
clinically in a recent wound which has been packed with gauze. When the
plug is introduced, the walls of the cavity consist of raw tissue with
numerous oozing blood vessels. On removing the packing on the fifth or
sixth day, the surface is found to be covered with minute, red,
papillary granulations, which are beginning to fill up the cavity. At
the edges the epithelium has proliferated and is covering over the newly
formed granulation tissue. As lymph and leucocytes escape from the
exposed surface there is a certain amount of serous or sero-purulent
discharge. On examining the wound at intervals of a few days, it is
found that the granulation tissue gradually increases in amount till the
gap is completely filled up, and that coincidently the epithelium
spreads in and covers over its surface. In course of time the epithelium
thickens, and as the granulation tissue is slowly replaced by young
cicatricial tissue, which has a peculiar tendency to contract and so to
obliterate the blood vessels in it, the scar that is left becomes
smooth, pale, and depressed. This method of healing is sometimes spoken
of as "healing by granulation"--although, as we have seen, it is by
granulation that all repair takes place.

_Healing by Union of two Granulating Surfaces._--In gaping wounds union
is sometimes obtained by bringing the two surfaces into apposition after
each has become covered with healthy granulations. The exudate on the
surfaces causes them to adhere, capillary loops pass from one to the
other, and their final fusion takes place by the further development of
granulation and cicatricial tissue.

_Reunion of Parts entirely Separated from the Body._--Small portions of
tissue, such as the end of a finger, the tip of the nose or a portion of