176 



STUDY OF PIG EMBRYOS. 



following order: A^. 5, the trigeminal ganglion; A^. 7, 8, the acustico-facial gan- 

 glion complex; Ot, the otocyst, an oval vesicle with very distinct epithelial walls. 



lOm.lC 



.V./o. — - 



,- Vert. IV. 



D.E. 



Fig. 113. — Pig, 12.0 mm. Transverse Series 5, Section 185. 

 com. Ganglionic commissure between hypoglossal and vagus nerves. com. I I, Ganglionic commissure with 

 fibers of the root of the spinal accessory nerve. D.E, Ductus endolymphaticus. F.b, Fore-brain. Md, 

 Medulla oblongata. N.^, Trigeminal ganglion. N.y,8, Acustico-facial ganglion. N^.io, Jugular 

 ganglion of the vagus. Ot, Otocyst. Ven.IV, Fourth ventricle. X 22 diams. 



Next the ninth or glosso-pharyngeal nerve (scarcely appearing in the section on 

 the right side of the embryo) is shown by the upper portion of its ganglion on the 



