158 MICROSCOPIC ANATOMY OF THE TEETH 



also clearly demonstrated by the following method. If an 

 unerupted tooth of Macropus is taken from its crypt when 

 the enamel forms a thin friable investment to the cap of 

 dentine, and scrapings from this enamel are allowed to fall 

 into glycerine and examined on a microscopic slide, it will 

 be seen that when they are broken up with needles the 

 fragments split into laminae which lie parallel to one another, 

 and both the longitudinal and transverse striae are very 

 clearly seen. 



FIG. 89. Transverse striation in developing enamel of Macropus. 



The most interesting point, however, demonstrated by 

 this method is the presence of granules and large calco- 

 spherites between and upon the laminae. 



In fig. 90, from a specimen prepared in this manner, the 

 laminae are seen to have separated in the direction of the 

 columns of the prisms, and a cross striation is also very 

 evident. Large globular bodies are seen between the laminae 

 and attached to their edges, while many of the larger bodies 

 are lying free in the surrounding fluid. 



Examination of a portion of these laminae with a high 

 power shows that these globular bodies are true calcospherites 

 of the radial type, and scattered granules are seen between 



