48 H. LISSER 



Fig. 21 Frontal section of human Embryo no. 128 (19.5 mm.) to show thyreoid 

 cartihige and M. cricoarytaenoideus lateralis, occ. h., occipital bone. 



Fig. 22 Frontal section of human Embryo no. 128 (19.5 mm.) laryngeal muscles 

 and cartilages. 



Fig. 23 Frontal section of human Embryo no. 128 (19.5 mm.) to show cricoid 

 cartilage, M. cricoarytaenoideus posterior, and thyreoid gland. 



Fig. 24 Graphic reconstruction of cricoid cartilage, posterior veiw, in hmnan 

 Embryo no. 22 (20 mm.) 3, anterior arch; J!^, posterior arch. 



Fig. 25 Graphic reconstruction of cricoid cartilage, lateral veiw in human Em- 

 bryo no. 22 (20 mm.). /, articular facet for thyreoid cartilage; 2, articular facet 

 for arytaenoid cartilage. 



Fig. 26 Same as fig. 25, showing extent of choudrification. tr. c, true cartilage; 

 pre. c, pre-cartilage (condensed mesenchyma). 



Fig. 27 Graphic reconstruction thyreoid cartilage in human Embryo no. 22 

 (20 mm.) showing extent of chodrification. 



Fig. 28 Graphic reconstruction of laryngeal cartilages in human Embryo no. 22 

 20 mm.) thy. hy., 1. thyreohyoid ligament. 



