'2 
W. L. WILLIAMS. 
1. Follicular Cysts. 
2. Fibrous Odontomes. 
3. Cementomata. 
4. Compound Follicular Odontomes. 
C. Aberrations of the Papilla. 
Radicular Odontomes. 
D. Aberrations of the Whole Tooth-Germ. 
Composite Odontomes. 
Were the subject well studied, we would doubtless find 
representatives of each class and sub-class in most of our do¬ 
mestic animals, especially in the horse, which seems far more 
prone to odontomes than our other patients. 
My observations have been confined wholly to the horse, 
and under the demands of every-day practice my means for 
the study of odontomes have not been in proportion to the 
material offered. 
1 have, however, had the good fortune to observe cases in 
each class and sub-class as outlined by Dr. Sutton, with the 
exception of fibrous odontomes and possibly also epithelial 
odontomes. 
In studying Dr. Sutton’s paper it will be observed that 
odontomes are very rare, in man and animals, in the incisor 
and canine teeth. It must be further remembered that the 
very slight development or total want in the horse, of the 
canines, makes aberrations in their growth very improbable 
indeed, and we thus have the molars as the only probable 
seat of odontomic aberrations, although a few exceptions to 
this rule occur. 
Bearing in mind the very complex character of the molars 
of the horse, in the intricate arrangement of the various tooth 
substances—presenting, as they do, an intermediary stage of 
development between the compound teeth of the elephant or 
mastodon and the single tooth of most smaller lower animals 
and of man—it will be readily understood that the epithelial 
odontomes of Dr. Sutton are not likely to occur in the same 
distinct form in the horse as is seen in the simple teeth of 
man, where the entire crown of the tooth is covered with 
pure enamel. 
In Fig. 1. we have, however, many of the characteristics of 
