THE TEETH. 647 



tine in the middle of the pulp-tissue, independent of the dentine composing 

 the walls of the pulp-chamber the so-called "pulp-stones." They, as is well 

 known, may be found either in connection with the dentine proper, by means 

 of a pedicle, or loosely imbedded in the connective tissue of the pulp. 



Most of these formations are composed of dentinal tissue, in the form 

 termed secondary dentine. Earer occurrences are those exclusively con- 

 structed of a laminated bone-tissue. Somewhat rarer are combinations of 

 both dentine and bone-tissue. The rarest are new formations of dentine 

 strictly identical with primary dentine. 



1. Pulp-stones of the Character of Secondary Dentine. The characteristic 

 feature of this variety is the presence of dentinal canaliculi irregularly scat- 

 tered throughout the calcined basis-substance. Sometimes the canaliculi 

 assume a tolerably well-marked radiation ; at other times, large masses of cal- 

 cified basis-substance are destitute of canaliculi, which, in scanty bundles, are 



FIG. 283. EBURNIFICATION OF THE PULP. 



L, irregular lamellae, traversed by radiating deutinal canaliculi ; CO, concentrically stri- 

 ated globules (osteo-dentine). Magnified 300 diameters. 



present toward the periphery of the pulp-stone. All the three varieties of 

 secondary dentine (see page 636) may be found. Portions of the basis-sub- 

 stance, especially toward the periphery, may exhibit delicate concentric lam- 

 inations. In the middle of an apparently homogeneous basis-substance, small, 

 lamellated territories may occur, containing a central corpuscle with branch- 

 ing offshoots somewhat resembling a bone-corpuscle. In sections of one 

 pulp-stone I have found numerous concentrically laminated territories, with 

 either distinct or indistinct bioplasson formations in their centers. The mass* 

 between the territories was partly granular, partly composed of a tissue, like 

 secondary dentine, with irregular canaliculi. Here and there medullary 



