SPLANCHNOLOGY 



149 



mucin which lubricates the mucous surface . These cells are found 

 in all mucous surfaces and prevent the surface from becoming dry. 

 There are a few goblet cells near the summits of the villi. Open- 



FiG. 37. — Histological studies of various anatomical parts. 



A. A transverse section of the first portion of the esophagus of a fowl, i. 

 The outer longitudinal muscular layer. 2, The circular muscular layer. 3, The 

 submucosa. 4, The muscularis mucosa. 5, Stroma. 6, Epithelial layer. 7, 

 The lenticular glands. 8, The lumen. 



B. A transverse section of the proventriculus. i. The outer longitudinal 

 muscular layer. 2, The middle muscular layer. 3, The inner longitudinal mus- 

 cular layer. 4, Stroma. s> The muscularis mucosa. 6, The submucosa. 7, 

 Stroma. 8, Tubular glands. 9, Tubulo-alveolar glands. 10, A tubulo-alveolar 

 gland with the tubular glands cut transversely. 11, The lumen of the proven- 

 triculus. 



C. A section of the inner wall of the gizzard. 1, The hyaline mucous mem- 

 brane. 2, Branched tubular glands. 3, Submucosa. 4, Muscle. 5, A con- 

 nective tissue septum. 



D. A transverse section of the small intestines, i, The outer longitudinal 

 muscular layer. 2, The inner circular muscular layer. 3, The muscularis 

 mucosa. 4, The stroma. 5, Brunner's glands. 6, A villus. 7, Mass of lym- 

 phoid tissue. 



E. A transverse section through the cecum, i, The outer longitudinal mus- 

 cular layer. 2, The inner circular muscular layer. 3, The submiicosa. 4, The 

 muscularis mucosa. 5, The stroma. 6, Tubular glands. 7, The lumen. 



F. The cerebellum showing the arbo-vitae. 1, White, fiber portion. ^, The 

 granular layer. 3, The layer of Purkinje cells. 4, The molecular layer. 



ings of simple intestinal tubular glands the duodenal glands, or the\ 

 / glands' formerly known as Brunner's glands, are located between the 

 villi. These glands secrete the succus entericus, or intestinal juice^ 

 These openings, or stomata, are lined with granular ceUsy The ■ 



