ZL 



LFL rf 





FIG. 312. DENTAL ANLAGES FROM A HUMAN FETUS 40 MM. LONG. 



Letters as in the preceding figure. LFL, labial lamina, or anlage of the groove 

 between the lip and the mandibular process; Pp, dental papilla; Z, outline of the 

 margin of the tongue; ZL, dental lamina. X 60. (After C. Rose.) 



FIG. 313. Two STAGES IN THE EARLY DEVELOPMENT OF THE TEETH, FROM A 25 MM. 

 PIG EMBRYO. 



In B is seen the developing bone and striped muscle of the lower jaw. In both 

 stages the dental papilla and the three layers of the enamel organ are clearly shown. 



332 



