LOWER INCISORS. 



1. At three years the central pennancnt incisors are well up, only the portion of the 

 table behind the m irk does not show much signs of wear. It is soon after two j-ears and 

 three months that the central sucking-teeth are shed. 



2. Soon after three years and three months, or more correctly, three years "off," 

 the lateral milk teeth are replaced by the permanent ones. 



3. Again at four years "off" the corner sucking teeth are replaced. When the 

 animal reaches five or thereabouts it has a full level set of permanent incisors, and the 

 mouth has a very neat and full appearance. The corner incisors show very little wear 

 upon their tables, unless in front of the mark, i.e., the so-called infundibuluni . 



4. If the corner incisors are carefully inspected in a horse that is rising six, it will be 

 seen that the hinder part of the table of the tooth is not in proper wear ; the front is, 

 however. This is the best evidence of a rising six years old. 



A. A section through a sucking or temporary incisor tooth. 



B. A section through an unworn permanent incisor. It illustrates the parts as follows : — 

 (a). Enamel covering a little lower on the front than the back. (h). The so-called mark 

 or infundihclum. {c). Dentine, {d). Cavity containing pulp. {e). Covering of fang or 

 root of tooth. 



C. Transverse section through a worn incisor tooth, showing the following parts : — 

 (a). The outer enamel ring. (1^). The inner enamel ring, which surrounds the central 

 mark. (c). Dentine, (d l). Mark or infimdib-iihuu. 



\_Facing page 50. 



