Figure 5: (Top panel) Low power view of the caudal duct ( 2). The letters a, b and c represent the foci shown in magnification (a), (b), and (c), respectively (hematoxylin-eosin stain). (a) shows the transition (arrow) between normal epidermis displaying granular layer and orthokeratosis to the parakeratotic squamous epithelium lining the duct ( 10, hematoxylin-eosin stain). (b) The lower portion of the blind duct is lined by pseudostratified ciliated epithelium, upper respiratory type ( 40, hematoxylin-eosin stain). (c) The duct is surrounded by seromucinous glands ( 10, hematoxylin-eosin stain).