508 GLANDS OF INTESTINES. 



rest, and lobulated in structure, occupy the margin of the opening 

 of the Eustachian tube. 



The (Esophageal glands are small lobulated bodies, situated in 

 the submucous tissue, and opening upon the surface of the reso- 

 phagus by a long excretory duct, which passes obliquely through 

 the mucous membrane. 



The Gastric follicles are long tubular follicular glands, situated 

 perpendicularly side by side in every part of the mucous membrane 

 of the stomach. At their terminations they are dilated into small 

 lateral pouches, which give them a clustered appearance. This 

 character is more clearly exhibited at the pyloric than at the cardiac 

 end of the stomach. They are intended, very probably, for the 

 secretion of the gastric fluid. 



The Duodenal or Brunner's glands,* are small flattened granular 

 bodies, compared collectively by Von Brunn to a second pancreas. 

 They resemble in structure the small salivary glands, so abundant 

 beneath the mucous membrane of the mouth and lips ; and, like 

 them, they open upon the surface by minute excretory ducts. They 

 are limited to the duodenum. 



The Solitary glands are of two kinds, those of the small and those 

 of the large intestine. The former are small circular patches, sur- 

 rounded by a zone or wreath of simple follicles. When opened, they 

 are seen to consist of a small flattened saccular cavity, containing a 

 mucous secretion, but having no excretory duct. They are chiefly 

 found in the lower part of the ileum. The solitary glands of the 

 large intestine are most abundant in the csecum and appendix caeci ; 

 they are small circular projections, flattened upon the surface, and 

 perforated in the centre by a minute excretory opening. 



The Aggregate, or Peyer's glands,] are situated near to the lower 

 end of the ileum, and occupy that portion of the intestine which is 

 opposite the attachment of the mesentery. To the naked eye they 

 present the appearance of oval disks, covered with small irregular 

 fissures ; but with the aid of the microscope they are seen to be 

 composed of numerous small circular patches, surrounded by simple 

 follicles, like the solitary glands of the small intestine. Each patch 

 corresponds with a flattened and closed sac, situated beneath the 

 membrane, but having no excretory opening, and the interspace 

 between the patches is occupied by flattened villi. 



The Simple follicles, or follicles of Lieberkuhn, are small pouches 

 of the mucous layer, dispersed in immense numbers over every part 

 of the mucous membrane. 



Muscular coat. The muscular coat of the pharynx consists of 

 five pairs of muscles, which have been already described. The 

 muscular coat of the rest of the alimentary canal is composed of 

 two planes of fibres, an external longitudinal, and an internal cir- 

 cular. 



* John Conrad von Brunn; "Glandula? Duodcni seu Pancreas Secundarium," 1715. 

 t John Conrad Peyer, an anatomist of Schauffhausen, in Switzerland. His essay, 

 " De Glandulis Intestinorum," was published in 1677. 



