2 CLINICAL VETERINARY MEDICINE AND SURGERY. 



occupies that position. It is of little importance whether the tooth be 

 temporary or permanent. The mere inclusion of a tooth will not 

 produce a dental cyst. In point of fact, one sometimes finds unde- 

 veloped teeth buried in foreign tissues, and cysts have been observed 

 in which the included tooth does not project into the interior of the 

 cyst at all, but is enclosed in its wall. 



Various theories have been advanced to explain the pathology 

 of these cysts. The most probable is that of Monsieur Malassez, 

 enunciated during his study of the paradental epithelial debris. This 

 author explains their origin by the persistence of some epithelial 

 debris around the included tooth, and considers them due to the 

 irritation produced during the growth of the tooth. Those containing 

 several teeth result from the formation of a cyst at some spot where 

 several tooth germs have been buried close together ; the teeth deve- 

 lop and break into the cyst cavity. 



I leave on one side the general history and pathology of these curious 

 growths ; I wish to speak particularly from the clinical standpoint, 

 and to restrict myself to dentigerous cysts of the temporo-auricular 

 region, which are by far the commonest and most interesting to the 

 practitioner. Their degree of frequence is established by statistics 

 long ago published by Lanzilotti and Generali. Of seventy-five cases 

 mentioned in the veterinary journals sixty-eight were of this character. 



I believe Mage-Grouille published the first authentic case in De 

 Fromage de Feugre's Corrcspondancc. He punctured a collection 

 of fluid developed between the left zygomatic process and ear of a 

 three-year-old colt. At the base of the cavity he found implanted in 

 the cranial wall a sort of " bony peg," which he removed. It was a 

 large, irregular molar, measuring two and three eighths inches in 

 length, and three and a half in circumference. 



Under the title of ' Eburnated Degeneration of the bony part of the 

 Temporal,' Rodet related in 1827 a second case of supernumerary teeth. 



The following year Benard recorded a third case in the Rccueil, 

 and corrected Rodet's diagnosis. You will find in one of Goubaux's 

 Reports, communicated to the Central Society of Veterinary Medi- 

 cine in 1853, an outline of the principal cases published at that date. 

 Among the more recent works relative to this question I may cite an 

 article of Macorps, inserted in the Annals of 'Veterinary Medicine of 

 i860, and the memoir of Lanzilotti and Generali, published in 1873 in 

 the Ga::zetta Vcterinaria. 



Our last case may be described in a few words. The animal is a 

 four-year-old horse, bought at Beauce a fortnight ago by a dealer, who 



