Plate XLMII 



Fig. 21. Reconstruction of the ectal surface of the oral epithelium of a lo 

 millimeter embryo. Columbia Collection, No. 113, X 600, reduced to j. 



Fig. 22. Frontal section of the broader portion of the orbital fold of the same 

 embryo, at the site indicated in the preceding figure, X 115, re- 

 duced to k. 



Angulus oris. 



Orbital inclusion. 



Orbital inclusion, pars lata. 



40. Lateral tongue swelling. 



41. Tuberculum impar. 

 44. .\lveolingual region. 

 60. Palate process. 

 6/. Mandibular nerve. 

 S6. Tubotympanic sulcus. 



