HEALING OF EXTERNAL WOUNDS. 
409 
The processes of repair apparently vary according to the 
severity of the injury, while in fact they are practically similar 
except in extent and length of time necessary to recovery. 
The exceptions to this are two. 
First: Those where there is such a trifling destruction of 
cells that simple regeneration of the essential surrounding cells 
is sufficient for repair. 
Second : Where the wound is somewhat greater in extent 
but still within the capacity of the connective tissue to repair 
by hyperplasia and regeneration without the intervention of 
embryonic and granulation tissues. 
By healing is meant the removal of foreign material from a 
wound and the replacement of the destroyed or degenerated 
tissues by new tissue. Hyperplastic and regenerative growth 
of tissue is ushered in by cell multiplication by karyokinesis 
and is inseparably associated with the phenomena of inflam¬ 
mation. In fact, so much so that it is impossible to consider 
one subject without involving the other. Proliferation occurs 
most readily when there is little inflammation present and only 
a slight exudate, for the presence of any irritant retards the 
process by increasing the inflammation and exudation and may 
lead to suppuration. 
The ability to form new tissue lies in the proliferative fac¬ 
ulty of the cells. These do not multiply under normal condi¬ 
tions, but when a wound is to be repaired some kinds of tissues 
proliferate with readiness and rapidity. 
Hyperplasia and regeneration of tissue are by no means con¬ 
fined to the repair of wounds, for they always accompany pro¬ 
ductive or proliferative inflammation. It is found that in the 
connective tissues is a reserve force which is ready and conven¬ 
ient whenever the tissues surrounding a wounded area, whether 
due to injury, degeneration or necrosis, cannot repair the breach. 
If the injury is beyond the capability of the surrounding tissues 
to repair, the space is filled by connective neoplasia or scar tis¬ 
sue. Because inflammation is always present in these processes 
it has been called proliferative inflammation and it is present 
