360 CHIKANOSUKE OGAWA 
Fig. 16 Respiratory epithelium. Still-born rabbit embryo, Silver impregnation. X 350. 
Fig. 17 Respiratory epithelium. Still-born rabbit embryo. Hematoxylin-eosin. X 600. 
Fig. 18 Respiratory epithelium. Rat. Two days after water injection. Silver impreg-_ 
nation. X 350. 
