200 OPERATIONS ON THE SKIN AND CELLULAE TISSUE. 



of the pus, and to be treated generally after the manner of similar 

 tumors in other parts of the body. But occasionally a filtration 

 of the pus takes place between the different layers of tissues, and 

 the abscesses become troublesome. To avoid their formation 

 there must be a complete and regular evacuation of the tract by 

 pressing out the contents once a day or oftener, according as 

 the discharge requires it. To avoid the possibility of the migra- 

 tion of the pus and the formation of a deep abscess, the operator 

 must be careful not to make a false tract with the needle during 

 its passage under the skin. 



(d) Excessive Granulations or Fungosities. — These often occur 

 at the openings of the tract, when the tape has been left in place 

 a long time. They are not of a serious character, and can be re- 

 moved by excision or cauterization. 



(e) Indurations. — These are also among the sequelae of setons 

 left in position too long, or when, after the removal of the tape, 

 care has not been taken to press out and thoroughly empty the 

 tract of any remaining portion of the discharge. These indurations 

 appear in the form of long, hardened cords, extending moi'e or 

 less in the original length of the setons. They often disappear 

 spontaneously, by a slow process of resorption, but in many cases 

 it becomes necessary to have recourse to friction with alterative 

 ointments composed of preparations of mercury or iodine. Deep 

 pointed cauterization, or their entire removal by dissection are also 

 recommended. 



ABLATION OF TUMOES. 



Under this heading are included the various modes of the divi- 

 sion of tissues involved in the removal of tumors — a tumor being, 

 as technically defined, a non-inflammatory mass, constituted by 

 tissues of new formation, and having a tendency to i^ersistency 

 and possible growth. 



The term ablation, of which the common definition is simj)ly 

 taking avmy, is in surgery employed to denote the excision or re- 

 moval of tumors — a tumor being, in a surgical sense, any morbid, 

 circumscribed enlargement affecting any of the structures or organs 

 of the body, sometimes harmless, and sometimes malignant and 

 fatal in their character and termination. 



The siu-gical means at the disposal of the veterinarian, by 

 which this operation is accomplished, are not so numerous as 



