CHAP. XXV.] 



THE INTESTINAL GLANDS. 



233 



and a rounded, obtuse base imbedded in the submucous tissue. Its 

 precise relation to the elements of the mucous membrane cannot 

 be exactly determined ; its wall seems to be formed of a structure 

 distinct from the basement layer of that membrane. It projects 

 among Lieberkiihn's tubes, and, in the small intestine, is concealed 

 and covered by the villi of the mucous membrane. Within it is 

 contained a variable quantity of nuclei and granular particles, 

 which, in the present state of our knowledge, must be viewed as a 

 secretion. How this secretion is discharged is a matter of uncer- 

 tainty, as no orifice has as yet been clearly demonstrated ; hence, 

 some anatomists regard these glands as closed vesicles, which burst 

 when distended to a certain point. 



Fig. 1G7. 



g 

 t 

 I 



Vertical section through a patch of Peyer's glands in the dog. a villi. & tubes of Lieberktihn, 

 with the apices of Peyer's glands, c. Submucous tissue with the glands of Peyer imbedded in it. 

 d. Muscular and peritoneal coats, e. Apex of one of Peyer's glands projecting among the tubes 

 of Lieberktthn. The glands are seen laid open by the section. Magnified about 20 diameters. 



Peyer s Glands* These may be regarded as aggregations of 

 solitary glands, forming circular or oval patches situated on the 

 free border of the intestine (fig. 166). They belong particularly 



* The glands, so long known by this title, may be called " Grew's glands " 

 with as much justice. They were discovered in several animals by our 

 countryman, Dr. Nehemiah Grew, who also delineated them with great accu- 

 racy, and described them in his lectures to the Eoyal Society, in the year 

 1676, before Peyer's book was published (1677). Dr. Grew's descriptions and 

 delineations may be found in an essay appended to his catalogue of the mu- 

 seum of the Royal Society, of which he was Curator, entitled " The Compara- 

 tive Anatomy of the Stomach and Guts begun." See the advertisement 

 prefixed to this work. 



VOL. II. R 



