654 PRINCIPLES OF VETERINARY SURGERY 



On transverse section of a diseased head the osseous 

 wall is seen to have disappeared and to have been replaced 

 by a circular area of new tissue that forces everything back. 

 (Fig. 113). The new tissue is of a lavender shade and studded 

 with a number of hsemorrhagic dots. Its consistency is firm 

 and fibrous, and when pressed a limited quantity of clear 

 serosity exudes. The neoplasm is equally developed on each 

 side and extends from the anterior nares to the pharynx, 

 gradually increasing in size posteriorly. The bony boundary 

 of the nasal cavities has completely disappeared, and the 

 mucous membrane is in close contact with the subjacent 

 neoplasm. 



x.t 

 Fig. 112. 

 Transverse Section Made Just Behind the Snout of a Normal Hog. 



The tissue of the tumor appears to be homogeneous 

 through the entire length of the maxillary bones. The teeth 

 are rather solidly implanted in the fibrous bed, but they are 

 generally bent sidewise. The alterations in the superior 

 maxillary are found, also, in the inferior maxillary, which 

 circumstance is important from the standpoint of the nature 

 and origin of the disease, in that it leads to the inference that 

 the inoculation does not take place in the nasal mucous mem- 

 brane, but probably through erosions of the buccal mucosa. 

 The examination of the inferior maxillary discloses almost 

 complete disappearance of the osseous tissue, separation of 

 the osseous lamellas and the displacement of the cancellated 



