Slide DMS141 [Monkey; submandibular gland; PTS]. These glands produce about 65% of the saliva and are of the mixed serous/mucous type. Like the parotid the parenchyma of these glands is divided into lobules by connective tissue septa. Note serous secretory acini are far more numerous than mucous types. Some of the mucous secretory units are capped with serous demilunes (see drawing below). Find intralobular intercalated and striated secretory ducts and the larger ducts into which these drain, located in the interlobular connective tissue.