84 
W. L. WILLIAMS. 
served some supposedly recovered cases which were not at all 
benefited. If these masses have a calyx or alveolus and the en¬ 
tire odontoid tumor is removed certainly permanent recovery 
should and no doubt does occur. 
The odontoid masses in the testicles and ovaries are of both 
scientific and practical interest, tending to render the genital 
gland useless and causing the testicle to remain abdominal in 
some cases. They frequently assume a form and histological 
structure closely simulating a normal tooth. 
Our chief interest must, however, be centred in those odon- 
tomes occurring within or near a normal alveolus and represent¬ 
ing either a normal tooth follicle or a germ emanating from or 
near by one of these. 
i\s we have insisted in our prior contribution, most of the 
serious diseases of horses’ teeth are due primarily to aberrations 
in their development and have their origin at an early age though 
coming to our notice sometimes only after a lapse of several 
years. In our experience fully 90 per cent, of major dental op¬ 
erations are necessitated by these aberrations, and when criti¬ 
cally studied a large proportion of the cases of so-called “caries” 
of the molars and of “ nasal gleet ” are due to this cause. 
Admitting the possibility and existence of primary caries 
of equine molars, we have as yet failed to secure a specimen ex¬ 
hibiting necrosis of the dentine in active progress except when 
evidently secondary to other important defects. True, most au¬ 
thors describe caries in equine molars and lead the student to 
believe it common, though Muller* agrees in his observations 
with our findings. 
Those authors who describe “ caries ” of horses’ molars usu¬ 
ally figure the disease as occurring at a part of the tooth in 
which dentine should not normally occur. In those specimens 
which we have been enabled to collect which simulate caries or 
which might by some be termed caries we find in addition to 
various irrelevant changes : 
o 
1. Deep infundibuli in the ivory column on the tabular sur- 
* Specie lien Chirurgie, .S'44. 
