COURSE OF HEALING PROCESS IN A WOUND. 305 



loses its color, and in a short time it is difficult to distinguish it 

 from the surrounding tissues. 



Healing by Suppuration or Second Intention. This appears when 

 the wound is left to itself, and, if the animal does not lick it, it 

 becomes quickly covered with dry blood and lymph, also a thick 

 crust, which varies in color between red and dark-brown, covering 

 over the edges of the wound. If the wound is licked from time 

 to time, we have a discharge of bloody, watery fluid. After this 

 the wound becomes covered with a veil-like gray covering, the 

 secretion becoming more and more copious and thicker, then yel- 

 lowish-gray, and iinally pure yellow (pus). The edges of the 

 wound become swollen and red, the gray covering of the edges 

 drops off in pieces, carried away by the pus or licked off by the 

 animal. From the second to the fourth day we see the appearance 

 of small red granulations from the wound. These increase in 

 number and finally fill up the spaces in the surface of the skin. 

 Now the active secretion of pus begins to stop. The skin grad- 

 ually contracts around the wound, the neighboring epithelial 

 border rises above the edges, and eventually forms a cicatrix. 

 The granulating surfaces, as a rule, shrink, contracting and draw- 

 ing together the cutaneous borders from all directions, finally 

 leaving a whitish somewhat depressed cicatrix. This is more 

 irregular, broader, and thicker than the cicatrix formed in wounds 

 healing by first intention. 



Healing under a dry scab occurs, as a rule, in small wounds 

 which are not exposed to infection or have not been licked. 

 Under this head we may class excoriations, cauterizations, various 

 small incised or superficial wounds which have been covered in 

 their early stages by antiseptic powders, such as boric acid, iodo- 

 form, or antiseptic collodion. The same effect is seen after the 

 use of the thermo-cautery. Dried blood, tissue fluid, etc., form a 

 scab which becomes adherent, and only when this scab is removed 

 by force does it produce bleeding. If it is not interfered with, it 

 drops off in from eight to fifteen days, according to the size of the 

 wound, and as a result we see a reddened, non-resistant cicatrix 

 which soon becomes pale and hard. If the scab drops off at an 

 early period from some other cause, we generally see distended, red, 

 irritable granulations, surrpunded by a cicatricial wall. 



Healing under a Moist Saab. This may be produced by follow- 



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