ELEPHANT. 649 



vascular membrane of moderate thickness, which is confluent with 

 the border of the base of the pulp, where it receives its principal 

 vessels. 



The account which Cuvier(l) has given of the formation of the 

 complex molars of the -Elephant is remarkably clear and comprehen- 

 sive, but is vitiated by the terms of the ' excretion-theory' in which 

 the different processes are explained; it is otherwise so minute and 

 accurate that it needs little more than the substitution of the language 

 of the ' conversion-theory' to convey all the requisite knowledge of 

 the process. 



Each molar of the Elephant is formed in the interior of a mem- 

 branous sac — the capsule, the form of which partakes of that of the 

 future tooth, being cubical in the first molar, oblong in the last, and 

 rhomboidal in most of the intermediate teeth ; but always decreasing 

 in vertical extent towards its posterior end, and closed at all points, 

 save where it is penetrated by vessels and nerves. It is lodged in 

 an osseoup chamber of the same form as itself, and usually in part 

 suspended freely (as at a, fig. 2, PL 146) in a large cavity excavated 

 in the maxillary bone ; the bony case being destined to form part 

 of the socket of the tooth. The exterior of the membranous capsule 

 is simple and vascular, as shown at m 5, fig. 1, PL 146 ; 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 towards that part of the capsule 

 ready to escape from the socket. These plates adhere only to the 

 bottom of the capsule ; their opposite extremity or summit is free 

 from all adhesion. 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 iden- 

 tical 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. 



(1) 'Annales du Museum,' torn, viii, (1806) p. 94. The account is repeated verbatim in 

 the posthumous edition of the * Ossemens Fossiles,' 1834. 



