socket of the tooth. The exterior of the membranous 

 capsule is simple and vascular, as shown at m 5, Fig. 73; 

 its internal surface gives attachment to numerous folds 

 or processes, as in most other ungulate animals. 



The dentinal pulp rises from the bottom of the capsule, 

 or that part which lines the deepest part of the alveolus, 

 in the form of transverse parallel plates extending to- 

 wards that part of the capsule ready to escape from the 

 socket. These plates adhere only to the bottom of the 

 capsule; their opposite extremity is free from all adhe- 

 sion. This summit is thinner than the base ; it might be 

 termed the edge of the plate ; but it is notched, or divided 

 into many digital processes. The tissue of these digitated 

 plates is identical with that of the dentinal pulp of simple 

 Mammalian teeth; it becomes also highly vascular at the 

 parts where the formation of the dentine is in active 

 progress. 



Processes of the capsule descend from its summit into 

 the interspaces of the dentinal pulp-plates, and conse- 

 quently resemble them in form ; but they adhere not only 

 by their base to the surface of the capsule next the mouth, 

 but also by their lateral margins to the sides of the cap- 

 sule, and thus resemble partition-walls, confining each 

 plate of the dentinal pulp to its proper chamber; the 

 margin of the partition opposite its attached base is free 

 in the interspace of the origins of the dentinal pulp- 

 plates. 



' The enamel organ, which Cuvier appears to have re- 

 cognized under the name of the internal layer of the cap- 

 sule, is distinguishable by its light blue sub-transparent 

 color and usual microscopic texture, adhering to the free 

 surface of the partitions formed by the true inner layer 



