IS4 



THE DISSECTION OF PIG EMBRYOS 



The anlages of those permanent teeth which correspond to the decidual, or 

 milk teeth, are developed in another series along the free edge of the dental 



Milk 

 molar I 



Aboral 

 prolonga- 

 tion of 

 dental 

 lamina 



Fig. 161. — Dental lamina and anlages of the milk teeth of the upper jaw from a fetus of 115 mm 



(Rose in KoUmann). 



Dental lamina 







Epidermis 



Outer enamel layer 

 Enamel pidp 

 Innf^ enamel layer 



Fig. 162.— Section through the upper first decidual incisor tooth from a 65 mm. human fetus. X 70. 



lamina (Fig. 160 D) and come to lie mesad'of the decidual teeth. In addition, 

 the anlages of three permanent molars are developed on each side, both above 

 and below, from a backward or aboral extension of the dental lamina, entirely 



