1S2 



STUDY OF PIG EMBRYOS. 



to the trigeminal ganglion, N. 5. The vein is cut twice, Jug' and Jug" , for it 

 curves around the ganglion, passing on the inside of the ganglion between it and 



.1/,/. 



Ven.iv. 



Ven.iii 



Fig. 115. — Pig, 12.0 mm. Transverse Series 5, Section 19S. 

 Ec, Ectoderm. F. b, Fore-brain. In/, Infundibular gland. Jitf, Jttff", Jugular vein. jV.j, Trigeminal gan- 

 glion. A'.7,S, Acustico-facial ganglion. N.g, Ganglion nodosum of the glossopharyngeal nerve. A r ./o. 

 Jug, Jugular ganglion of the vagus nerve. .V.//, Root of the spinal accessory nerve. .W, Medulla oblon- 

 gata. Ot, Otocyst. S/i; Stri;> acusticse. Ven.iii, Third ventricle. W-ii.iv, Fourth ventricle. >;' 22 diams. 



the wall of the brain. At this stage, however, it has begun to expand outward 

 behind, in front of, and below the ganglion. The expansion of the vein outward 



