16 PRINCIPLES OF YETEEINAEY SUEGEEY 



the -wound shows a dry pinkish seam moving toward tha 

 centre of the granulating surface, being followed by a bluish 

 dry seam upon the pigmented skin; this process continues 

 until the whole granulating surface is skinned over. 



Describe the microscopical changes in healing by second 

 intention. 

 On the whole there is but little difference in those 

 observed in healing per primam and those per secundam 

 intentionem. The main point of difference lies in the fact 

 that on account of the presence of pus-producing cocci decided 

 irritation of the tissues is produced, as a result of which large 

 numbers of leucocytes emigrate. Otherwise the infiltration 

 of the wound edges, the formation of fibroblasts, vasculariza- 

 tion — that is, the budding of the capillary vessels — the chang- 

 ing of the fibroblasts into fibrillar connective tissue, is in no 

 wise different from healing by primary union. 



Define healing by third intention. 



It consists in the union of two suppurating granulating • 

 surfaces. 



What steps are necessary to secure healing per tertiam 9 



Absolute disinfection of the granulating surface with 

 perfect coaptation of the wound edges held in place by an 

 exact suture. 



To what eodent is healing per tertiam applicable 9 



It is a most valuable method and should always be 

 attempted, to bring about rapid and permanent union. 



How long after the primary injury occurred, may healing pet 

 tertiam be possible f 



To avoid ugly scars— for instance, about the head of 

 valuable horses— a wound of a week's standing can be healed 

 by third intention. 



