ANIMAL DENTISTRY. 



237 



though quite large, will always heal eventually in the young 

 ^ horse but may threaten to become permanent in horses past 

 the age of eighteen years. The most aggravated forms occur 

 from comminuted fractures. 



Fig. 153. 

 Prof. Edw. Merillat's Operation for Closing Chronic Skull Perforatio::-. 



A. 3rd step of operation. 



I, 2. "Melon slice" resection of the skin. See description. 



B. 4th step of operation. See description. 



C. 6th step of operation. See description. 



Treatment — Large perforations accompanied with loss 

 of considerable skin may be incurable, but when the orifice 



