412 
J. A. SLOAN. 
and later proliferation of connective tissue from the sound tis¬ 
sue through the infiltrated area and into the wound, which fi¬ 
nally firmly binds the edges and constitutes healing by primary 
union. Proliferation of epithelium completes the process. 
As an aid to primary union these steps should be observed: 
First: Arrest and prevent haemorrhage. 
Second : To remove all foreign substances. 
Third : Apply suitable bandages both to keep the parts in 
close approximation and also to prevent the entrance of patho¬ 
genic germs. About the shortest possible time for these 
wounds to heal under the most favorable circumstances is seven 
to eight days. 
Healing by granulation, or so-called second intention, is 
seen in wounds where the changes are visible to the unaided 
eye and where there has been extensive destruction of tissue. 
This process consists of three stages. 
First: The formation of a deteriorated or embryonic tis¬ 
sue which develops into second. Granulation tissue, and 
Third : Completes the repair by a further 1 change into 
cicatricial tissue. This process is entirely competent to repair 
any wound or to make an uninterrupted continuity of tissues. 
The repair is not of normal tissue and there is a loss of func¬ 
tion because of the intervention and usually the preponderance 
of the connective tissue. The normal tissues do not possess 
the ability to close up the wound. 
Embryonic tissue consists largely of cells and blood vessels, 
and is never found except where the injury is beyond the 
ability of the surrounding tissues to repair it. The cells are 
mostly small, rounded in shape and infiltrated with leucocytes— 
mono and polynuclear—which have emigrated from the circu¬ 
lation. The number of leucocytes determines the intensity of 
the inflammation present and conversely the rapidity of recov¬ 
ery. The cells of embryonic tissue have been called prolifera¬ 
tive, or formative cells, because they give rise to the future tis¬ 
sue. In the early stage of its development it depends upon the 
tissue from which it sprung for its support, but later blood 
