THE TEETH. 39 



iiber die Beihtilfe der Nerven zur Speichelsecretion/ in f Mitth. 

 der Ziirch. nat. Ges./ 1850, Nos. 53 and 54, and ' Zeitschr. f. 

 rat. Med./ 1851 j C. J. Baur, ' Ueber den Bau der Zunge/ in 

 Meckel's * Archiv/ 1822, p. 350; P. N. Gerdy, • De la Struc- 

 ture de la Langue/ in ' Recherches d'Anatomie, de Physiologie, 

 et de Pathologie/ Paris, 1823; P. F. Blandin ' Sur la struc- 

 ture de la Langue/ in the 'Archiv. gener. de Medecine/ 

 1823 ; J. Zaglas on the f Muscular Structure of the Tongue of 

 Man and certain Mammalia/ in the ' Annals of Anatomy and 

 Physiology/ ed. by J. Goodsir, 1850, I, p. 1 ; H. Hyde Salter, 

 Art. ' Tongue/ in Todd's * Cycl. of Anat./ iv, June and Sept., 

 1850 ; C. B. Briihl, ' Ueber den Bau der Zunge der Haussauge- 

 thiere/ in f Kleine Beitrage zur Anatomie d. Haussaugethiere/ 

 Wien 1850, pp. 1-6 ; Sappey, ' Ueber die Lymphgefasse der 

 Zunge/ in f Comptes rendus/ 1847, p. 26; and 'Froriep's 

 Notizen/ 1848, vi, p. 88. Besides these, compare the anatomi- 

 cal works of E. H. Weber, Valentin (im Handw. d. Phys.), 

 Todd and Bowman, Henle, Arnold, Huschke, Krause, and 

 myself; the figures of Berres, Arnold, and Langenbeck. 



D. OP THE TEETH. 



§137. 



The teeth are hard organs inserted into the alveolar processes 

 of the jaws, which although to some extent identical in struc- 

 ture with bone, and in other respects clearly allied to it, must, 

 from their development, be regarded as modifications of the 

 mucous membrane. 



In every tooth we must distinguish the tooth proper, and the 

 soft structures ; the former consists of a free part, the crown, 

 and of an imbedded portion, the simple or multiple fangs, 

 whose special forms are treated of in anatomical works ; they 

 contain internally a small cavity, the pulp cavity, which ex- 

 tends through each fang as an elongated canal, opening at its 

 point by a simple, or more rarely double (Havers, Raschkow), 

 fine aperture. 



Among the soft parts we may enumerate first, the gum, 

 gingiva, a dense mass formed by the union of the mucous 

 membrane and of the periosteum of the jaw, which surrounds 



