10 
W. L. WILLIAMS. 
I 
can only be surmised by the fetor of the breath and nasal 
discharge. The causes which lead to suppuration of odon- 
tomes are probably various, but may as a rule be referred to 
one of two conditions. First, when accompanied by consider-' 
able cystic formation, the rupture of the cyst will almost in¬ 
evitably lead to suppuration. 
The second and undoubtedly more fertile and serious 
cause of suppuration lies in the imperfect development of the 
tooth crown, by which there is an open communication ex¬ 
tending from the crown up through the central portion of the 
tooth, between the inverted layers of enamel up to the fang, 
and into the mal-developed tooth follicle, through which food 
and other adventitious matter may readily pass and incite the 
suppurative process. By many these openings are regarded 
as the result of caries of the tooth, but a closer examination of 
a series of cases will develop the fact that essential caries of 
the molars of horses is very rare, and that this defect is 
primarily in the tooth germ, and that the inverted layer of 
enamel is not continuous at the bottom, but open, and that the 
cementous which should bind the enamel together throughout 
the length of the tooth is wanting, leave a free opening to 
the tooth germ. This is well illustrated in Fig. ib, where 
the fifth molar, as is shown by the wire passing through its 
center, is traversed from crown to follicle by an opening 
which was ready formed before erupting. In the same Fig. 
i a is shown the recently erupted fourth molar in the same 
condition. This same state is also well shown in Figs. 2, 3, 
and 6, and to a still greater extent, resulting in the longitudi¬ 
nal splitting of the tooth in Fig. 12 and 15, the series serving 
well to demonstrate that the opening is primary and if caries 
be found present, it is secondary. 
The treatment of odontomes can probably be best outlined 
by a series of cases occurring in practice and representing 
fairly well the various classes into which they have been 
divided. 
As previously noted, the first class aberrations of the 
enamel organ is most nearly represented by Fig. 1. 
The animal was an unusually large, vigorous, high grade 
