56 PHYSIOLOGY FOR THE LABORATORY. 



Observe : 



a. In the centre is the pulp cavity, which is filled during 

 life with a soft pulp containing blood-vessels and nerves. 



b. The dentine is the hard part around the pulp cavity. 



c. The enamel covers the dentine on the crown. How 

 far does it extend? 



d. The cement covers the dentine on the root. How far 

 does it extend? 



e. Sketch. 



2. Study the same slide with the compound microscope, 

 and observe the structure of the different parts. 



C. The Different Kinds of Teeth. 

 Materials. An incisor, a canine, a bicuspid, and a molar tooth. 



1. Identify the following kinds of teeth : 



a. The incisor with a wedge-shaped crown. 



b. The canine with a pointed crown. 



c. The bicuspid, or premolar, with a cuboidal crown. 



d. The molar with an irregular crown. 



e. Sketch one tooth of each kind. 



2. Compare the parts in the different teeth. 



a. How many cusps or points has each ? 



b. How many fangs has each? 



3. Arrange them on the table as they are in the jaw. 



4. A dental formula is often used as a short method to 



indicate the number of teeth. The numerator 

 indicates the number of teeth in one side of the 



