OSSICULA AUDITUS IN THE HIGHER MAMMALIA. 
925 
tensor tympani muscle and neck of malleus, hyoidean cartilage, 
facial nerve, and stapedius muscle, periotic capsule, mandibular 
cartilage and mandible. 
Fig. 39. Head of Pig embryo 1*4 centim. in length X 14, somewhat diagrammatic, 
designed to show the cartilages of the first two post-oral arches, the periotic 
capsule and semicircular canals, ganglion and trunk of facial with its mandi¬ 
bular branch, ganglion of ninth nerve, gasserian ganglion with its ophthalmic, 
maxillary and mandibular branches, primitive jugular vein, cerebral hemis¬ 
phere, vesicle of third ventricle, midbrain, cerebellum, medulla oblongata, 
ventricles, auricle and aortic bulb of heart, fore-limb, optic cup, olfactory pit, 
and maxillary, mandibular, hyoid, and indications of first and second 
branchial arches. 
Fig. 40. Eight bulla and periotic bone of adult Eat X 10 (parts of the bony meatus 
auditorius and periotic have been removed to expose the external ossicles 
in situ), showing mandibular process (what Doran calls process head) of 
malleus, lamina of papery bone between this process and tubercle at junction 
of neck and manubrium (the free edge of which is called processus gracilis 
by Doran), posterior process (Doran’s orbicular apophysis), manubrium 
mallei, body and crura of incus, ossified hyoidean cartilage (tympano-hyal of 
Flower), facial nerve with its mandibular branch, bulla, and Eustachian 
portion of bulla, articulation between bulla and petrosal. 
Fig. 40, A. Stapes of adult Eat X 10, showing head, crura, and base, 
with an attempt to show the fluted condition of these, and 
tubercle on posterior crus for stapedius muscle. 
Fig. 40, B. Long crus and orbicular apophysis of incus X 10, showing 
pedicular attachment of orbicular apophysis to long crus. 
