THE EAR. 



anterior ligament of the malleus and the accessory mesial ligament of the mandibular 

 articulation) and partly by a thin slip of membrane bone which develops in the perichondrium. 

 and becomes the processus gracilis of the malleus. Besides this the malleus has two ossifica- 

 tion centres, one in the head, the other in the manubrium. which appear at the end of the 

 third or the beginning of the fourth month. About the same time an ossification centre 

 appears in the body of the incus, and from this the whole of the bone is formed, except the 



Fig. 100. SECTION* THROUGH STAPES AND FEXESTRA OVALTS. (Brunner.) 



lenticular process, which appears as an epiphysis. The stapes ossifies somewhat later than the 

 other ossicles, and from four centres one for the head, one for each cms. and one for the base. 



Ligaments. In the articulations of the small bones of the ear with one another 

 the connection is strengthened by ligamentous fibres. 



Their attachment to the walls of the tympanum is effected chiefly by the 

 following ligaments, as well as by the reflections of the mucous membrane lining 

 that cavity. 



The anterior ligament of the malleus (figs. 00, I. a, and 101, La. m) is a 

 comparatively strong and broad band of fibres, which connects the base of the 

 processus gracilis and the anterior part of the malleus above this process with 

 the anterior wall of the tympanum close to the Glaserian fissure. The part 

 of the ligament which passes out of the Glaserian fissure was long thought to 

 be muscular (laxator tympani auct.), but most observers agree in denying the 



