104 VETERINARY DENTAL SURGERT. 



The fourth variety consists of fungous growth 

 very firm and containing small spicules of bone. 

 This form very much resembles osteo-sarcoma. It, 

 like osteo-sarcoma has a malignant character, and 

 seems to be dependent upon some constitutional 

 diathesis. It is very rarely noticed in horses ; cattle 

 however, suffer occasionally from its effects. 



Exostoses present a variety of external forms, 

 varying from a soft, spongy and cellular mass to a 

 very compact and dense osseous tissue. 

 SYMPTOMS. 



These exostoses may exist for a very long time 

 without giving rise to any serious symptoms. It is 

 rarely that the presence of the disease is suspected 

 previous to the bulging of the external walls of the 

 sinus. Occasionally however, they exert a pressure 

 upon the turbinated bones, causing more or less 

 difficulty in breathing. It is only when the sinuses 

 are opened up with the trephine that their presence 

 can be definitely ascertained. Sometimes there will 

 be a discharge of a fetid character taking place from 

 the nostrils. Percussion ,will enable us to diagnose 

 a filling up of the sinus, but as this may be due to a 

 variety of causes, all of which present similar symp- 

 toms, we can not arrive at a true diagnosis. 



The author has repeatedly found the sinus, 

 especially the inferior maxillary, partially or wholly 

 f Ikd up with these bony growths, when trephining 



