292 



VETERINARY PHYSIOLOGY 



The inside of the mouth of the ox has papillas sloping 

 inwards. These help to prevent the food from falling out. 



In ruminants the incisor 

 teeth are loosely fixed, 

 and meet the dental pad 

 obliquely. This arrangement 

 prevents injury to the dental 

 pad. 



The teeth of the horse are 

 peculiar in having an invagina- 

 tion of the enamel covering of 

 the crown. As the crown 

 wears, there comes to be two 

 consecutive rings of hard 

 enamel, enclosing softer 

 cement. This provides an 

 uneven surface, well suited to 

 the grinding of the food. 

 The horse has incisors in both 

 the upper and the lower jaw, 

 and these are used to bite 

 the grass in feeding. The 

 horse thus crops closer than 

 the ox. 



The incisor teeth of the 

 young horse are vertically 

 placed. With use they gradu- 

 ally come to assume an oblique 

 position and get pushed out 



duodenum; Li., Liver; P., pan- of their SOcketS, SO that the 



creas; /., jejunum; /., ileum; ^^^^^ ^^^ reduCcd in length 



v., vermiform appendix, present in o r x \ 



man and in rabbit ; Col., colon ; and the shape ot tlie teeth 



i?., rectum. altered. The shape and slope 



of the teeth, and the extent of wear on the crowns, give an 

 indication of the age of the animal. 



The complex joint of the upper and lower jaws in 

 herbivora allows the movements in mastication to be not 

 only up and down, but also lateral, and to some extent from 

 front to rear. This freedom of movement is more marked in 



Fig. 142. — Diagram of the Parts of 

 the Alimentary Canal, from 

 Mouth to Anus. T., tonsils ; Ph., 

 pharynx ; S.O., salivary glands ; 

 Oe., oesophagus ; C, cardiac, Py., 

 pyloric portion of stomach ; D., 



