A HISTOLOGICAL AND HISTOCHEMICAL STUDY OF THE DEVELOPMENT OF SALIVARY GLANDS IN THE CHICK (GALLUS DOMESTICUS)

Abstract

The anterior submaxillary glands of the domestic fowl are paired, compound tubular glands. Each is divided into four lobes and each lobe is composed of branching lobules. Secretory acini are distributed along the lobules and each lobule drains into the oral cavity by a separate duct. The lobules originate as ingrowths of the oral epithelium at the 9-day incubation stage. These primordia later increase in number and length, and become branched. The secretory product is produced by both the acinar and duct cells and is demonstrable at the 14-day incubation stage. It is a mucous secretion containing sulfated mucopolysaccharides and mucoproteins. Sialomucin, if present, could not be demonstrated. The secretory product increases in amount within the cells and lumina during the prehatching period. The duct and acinar cells stain positively for ribonucleic acid and alkaline and acid phosphatase, and possess mitochondria and Golgi bodies. The evolution of these substances and organelles parallels cytogenesis and the rate of elaboration of the secretory product. Lipids are present only as components of the cell organelles.