The cytoplasm of the mucous cells (HA7) is very light and vesicular. The nucleus is at the base of the cell, often flattened against the basal cell membrane. Most of the serous cells are in serous demilunes that form caps over the mucous acini (arrows, HA7). They secrete into the adjacent mucous acinar lumens through intercellular canaliculi. The serous cells have darker staining cytoplasms than the mucous cells and their nuclei are more rounded. At the lower center is an intralobular duct (i).