TEETH OF THE ELErilANT. 277 



placed by the active reparative power of these highly 

 vascular bodies. The hole formed by the ball in the base 

 of the tusk is then more or less completely filled up by 

 a thick coat of cement from without, and of osteo-dentine 

 from within. 



By the continued progress of growth, the ball so in- 

 closed is carried forwards, in the course indicated by the 

 arrow in Fig. 73, to the middle of the solidified exserted 

 part of the tusk. Should the ball have penetrated the 

 base of the tusk of a young elephant, it may be carried 

 forwards by the uninterrupted growth and wear of the 

 tusk, until that base has become the apex, and be finally 

 exposed and discharged by the continual abrasion to 

 which the apex of the tusk is subjected. 



I had the tusk and pulp of the great elephant at the 

 Zoological Gardens longitudinally divided, soon after the 

 death of that animal in the summer of 1847. Although 

 the pulp could be easily detached from the inner surface 

 of the pulp-cavity, it was not without a certain resistance ; 

 and when the edges of the coadapted pulp and tooth were 

 examined by a strong lens, the filamentary processes from 

 the outer surface of the pulp could be seen stretching as 

 they were withdrawn from the dentinal tubes before they 

 broke. They are so minute that, to the naked eye, the 

 detached surface of the pulp seems to be entire, and Cu- 

 vier was thus deceived in concluding that there was no 

 organic connection between the pulp and the ivor}^. 



The molar teeth of the elephant are remarkable for 

 their great size, even in relation to the bulk of the ani- 

 mal, and for the extreme complexity of their structure. 

 The crown, of which a great proportion is buried in the 

 socket, and very little more than the grinding surface 

 appears above the gum, is deeply divided into a number 

 24 



