IN HERBIVOROUS ANIMALS. 213 
of his proprietor, “ had a double row of teeth in the upper 
jaw.” 
This anomaly may present itself under different forms. Some- 
times the supernumerary tooth is situated in the one or the other 
jaw, in front of the normal range of molars, without having a corre- 
spondent tooth in the opponent jaw. At other times it is placed 
either within or without the arcade, without having, no more than 
in the other case just mentioned, a correspondent against which 
it may rub in the antagonist jaw. In practice this is designated 
extra tooth, or wolf-tooth. This kind of anomaly obtains more 
frequently in the deviation of a normal tooth than in the addition 
in the range of a supernumerary one. 
In the first instance, it is often not very long before the masti- 
cation encounters an obstacle in the exuberance of the super- 
numerary tooth, of which the discontinued growth is not limited 
by a regularly exercised friction. A day arrives, in fact, in which, 
under the influence of this growth, this same tooth finishes by 
passing the level of the others, and by attacking, in prolonging it- 
self, the sharpish border of the antagonist maxilla at that region 
commonly called the bars. Then the mucous membrane of this 
part of the mouth, murdered by the continual shock which it 
suffers, ulcerates, and leaves the bone naked. The latter, itself 
contused, mortifies and exfoliates. If the cause continues in action, 
after the exfoliation is produced, the bone, softened by the in- 
flammation at the region of the exfoliation, becomes the seat of 
insterstitial suppuration, and caries is consecutively established : 
then, the evil still progressing, the maxilla tumefies, and at length 
displays the pathological form designated by the name of osteo- 
sarcoma. 
In the second case, when the supernumerary tooth is placed either 
within or without the arcade, it offers an obstacle by its presence, 
in the commencement, to the motions of the tongue and cheeks, 
of which it excoriates the mucous lining. From thence a hinderance 
in the mastication, which hinderance increases from day to day in a 
ratio proportionally as the lengthening of the tooth augments the 
intensity of the cause which produced the first evil effects. 
Let us add, that the irregularity in the rows of the teeth to 
which the supernumerary organ leads by its presence, has for its 
necessary consequences the opposition to the exact relation be- 
tween the dental arcades, and then to the approach of the jaws. 
Hence, also, an irregularity in the friction, and consequently in the 
wear — an irregularity which permits the exuberance of the borders 
of the tables, either externally or internally, and which finally has, 
for a definitive result, the placing of an obstacle almost complete 
to the performance of the all-important function of mastication. 
VOL. XVII. F f 
