INOCULATION INTO GREAT SEROUS CAVITIES. 249 



needle is introduced into the subcutaneous tissues along 

 the edge of the incision. In this case they are to pass 

 into the abdominal cavity and out again, entering at one 

 side of the line of incision and leaving at the other, 

 as indicated by the solid and dotted lines in Fig. 48. 

 (The figure indicates the primary opening through the 

 skin. The longitudinal dotted line shows the opening to 



FIG. 48. 



Diagram of skin incision and sutures in laparotomy on animals. 



be made into the abdomen ; the transverse dotted lines, 

 with their loose ends, represent the sutures as placed 

 in position before the abdomen is opened ; it will be seen 

 that these sutures in all cases pass through the subcuta- 

 neous tissues only and do not penetrate the skin proper.) 

 The opening through the remaining layers may now 

 be completed ; the bit of tissue is deposited in the peri- 

 toneal cavity, under precautions that will exclude all 

 else, the edges of the wound drawn evenly and gently 

 together by tying the sutures, and the lines of incision 

 dressed with collodion. It should be needless to say 

 that this operation must be conducted under the strictest 



