234 



THE ESSENTIALS OF HISTOLOGY 



FIG. 271. SECTION OF ONE OF THE HUMAN SEMICIRCULAR CANALS. (Magnified.) 



1, osseous wall ; 2, fibrous bands with included blood-vessels, united at 3 with the periosteum ; 

 4, membranous canal with its three layers ; 5, short fibrous bands (with intervening 

 spaces) uniting the membranous canal firmly to the periosteum ; 6, union of its outermost 

 layer with the periosteum. 



FIG. 272. SECTION OF MEMBRANOUS SEMICIRCULAR CANAL. (Much magnified.) 



1, outer fibrous layer ; 2, tunica propria ; 3, 6, papilliform projections with epithelial covering; 

 5, fixed side of the canal, with very thin tunica propria without papillae; 7, fibrous bands 

 passing to periosteum. 



