GENERAL ANATOMY OF EMBRYO OF 12 MM. 



167 



Cbl. 



Ver.. IV 



M.b, 



Md.ob, 



^ 



^. 



Ot. 



-£.Z 



C.3 



■^ 



-rec. L. 



G5 



Mab 



Op 



Mx 



\J 



Na 



Hen, 



I op. 



H 



Fig. 107. — Pig Embryo of 12.0 mm. Reconstruction from the Transverse Sections, Series 5. 

 To show especially the cephalic nerves, c.i, c.2, r.j, Cervical nerves. Cbl, Cerebellum, com, Ganglionic 

 commissure connecting with the jugular ganglion, j. Dien, Diencephalon. ex. External branch of the 

 spinal accessory nerve. F, Froriep's ganglion, which in man completely disappears. 6" .5, Gasserian 

 ganglion. H, Cerebral hemisphere. ;', Jugular ganglion. Z, Lens. M.b, Mid-brain. Mdb, Mandibular 

 process. Md.ob, Medulla oblongata. Mx, Maxillary process, n. Ganglion nodosum. Na, Nasal pit. 

 Op, Optic cup. Ot, Otocyst. reel. Recurrent laryngeal nerve. Ven./V, Roof of fourth ventricle, j, 

 Oculomotor nerve. 4, Trochlear nerve, j", Trigeminal nerve. 6, Abducens nerve. 7, Facial nerve. 

 8, Vestibular ganglion. 9, Petrosal ganglion. 10, Vagus nerve. //, Spinal accessory nerve. 12, Hypo- 

 glossal nerve. 5 op marks the ophthalmic division of the fifth nerve ; 5 is on the vestibular ganglion, 

 immediately below which lies the cochlear ganglion ; the seventh nerve has two branches, of which the 

 anterior becomes the chorda tympani ; of the two branches of the ninth nerve, the anterior becomes the 

 tympanic, and the posterior the lingual nerve of the adult. X 20 diams. — [Drawn by Dr. F. T. Lewis.) 



