THE TEETH. 



The teeth are described by Cuivier as "mechanical in- 

 struments in the vertebrated animals, at the entrance of the 

 alimentary canal, designed to seize, cut, tear, bruise, and grind 

 nutritive substances, before their transmission to the mouth, 

 pharynx, and the oesophagus." 



Professor Owen says : " They present many varieties as to 

 number, size, form, structure, position, and mode of attachment, 

 but are principally adapted for seizing, tearing, dividing, pound- 

 ing, and grinding the food. In some species they are modified 

 to serve as formidable weapons of offense and defense ; in others 

 as aids in locomotion, means of anchorage, instruments for 

 uprooting or cutting down trees, or for transport and working 

 of building materials." 



Chauveau says : " Identical in all of our domesticated 

 animals, by their general disposition, their mode of development, 

 and their structure, in their external conformation these organs 

 present notable differences the study of which offers the greatest 

 interest to the naturalist, for it is on the form of its teeth that 

 an animal depends for its alimentation. It is. the regime^ in its 

 turn, which dominates the instincts and commands the diverse 

 modifications in the apparatus of the economy ; and there re- 

 sults from this law of harmony so striking a correlation between 

 the arrangement of the teeth and the conformation of the other 

 organs, that an anatomist may truly say : " Give me the tooth 

 of an animal, and I will tell you its habits and its structure." 



All of the domestic animals have two sets of teeth : first, 

 those o^ first dentliion^ which appear at or soon after birth, 

 which are known as foetal^ temporary^ miJlc^ deciduous^ or 

 caducous teeth ; second, those of the second dentition^ which are 

 known as replacing^ persistent^ or permanent teeth. 



