444 



becomes covered with a layer of embryonic and placoid cells, of which 

 the superficial ones degenerate into pus cells, and thus the surface is 

 kept moist by a layer of whitish, creamy pus. In the deeper layer of 

 cells miuute loops of capillary blood-vessels start up, cause the small 

 rounded elevations known as granulations. In this way the deeper 

 layer of cells receiving a blood supply is transformed into connective 

 tissue, and from its surface new loops of blood vessels start into the 

 layer above, and thus layer after layer of new tissue is formed, and the 

 breach caused by the wound is gradually filled up. The new tissue as 

 formed undergoes a steady contraction, drawing iu the adjacent skin 

 over the wound, and hence large wounds healed in this way have the 

 skin more or less puckered around them. 



(3) By secondary adhesion, in which two granulating lips of a wound 

 having b.een brought together and kept in apposition, union takes place 

 through the medium of the cells, as in primary adhesion. 



(4) By scabbing, in which the exudation on the surface of the wound 

 dries up into a firm scab, under which the process of repair goes on by 

 the development of tissue from the deeper cells, as in adhesion. 



In treating clean, incised wounds, attempts should be made to secure 

 healing by primary adhesion, even in the horse. Bleeding should first 

 be arrested, or nearly so, by applying a cold or hot sponge, or by tying 

 bleeding vessels, and the lips of the wound should then be closed ac- 

 curately, without any twisting or overlapping. In small wounds pieces 

 of sticking plaster may be used, the lips of the wound having first been 

 smoothly shaved, so that they may adhere firmly. In larger wounds 

 the wound may be sewed with a curved surgical needle and a silk 

 thread dipped in a solution of carbolic acid. The stitches may be con- 

 tinued from end to end of the wound and the thread prevented from 

 slipping and loosening by a knot at each end ; or the stitches may be 

 independent, the two ends being tied together across the wound. In 

 such cases they may be one quarter to one-third inch apart ; or the lips 

 of the wound may be pinned together, the pins in a simple skin wound 

 being inserted one-eighth inch from the edge, and when both lips have 

 been transfixed in this way a thread (or hair) carried successively 

 around the two ends of the pin and made to describe a figure 8 will 

 hold the wound close. When the stitching is not continuous from end 

 to end of the wound the apposition of the edges will be rendered more 

 perfect by the application of strips of sticking plaster in the intervals. 



When eflbrts at primary union have failed and pus has formed, or 

 fermentative changes have occurred on the raw surfaces and the lips 

 gape more or less, some antiseptic dressing will be required, as in the 

 case of lacerated and contused wounds. 



In cases where an incised wound has had foreign bodies or septic 

 ferments introduced into it, these should first be removed. A current 

 of water that has been boiled and cooled is one of the best methods of 

 cleansing a wound, and there is no objection to the addition of one- 



