FIGURE 5 



Section of head of human embryo of 20 mm., parallel to planmn basale, but at 

 higher level than plate 4. 



1, Slender area of basal plate 



2, Union of otic capsule to basal plate 



3, Anlage of ligamentum dentis epis- 



trophei 



4, Costal bar of lamina alaris 



5, Transverse process of occipital 



vertebra 



6, Layer of perichondrium separating 



costal bar from transverse process 



7, Cranio-mesial process of paracon- 



dyloid process 



8, Reichert's cartilage 



9, Ala orbitalis 

 10, Distal extremity, processus ali 



cochlearis 

 //, Membranous anlage of side wall of 



skull 



12, Stapes 



13, Malleus 

 H, Incus 



15, Interhyale 



16, Crista parotica 



17, Proximal end, Reichert's cartilage 



18, Processus mastoideus 



636 



