THE MEDULLA OBLONGATA AND CEREBELLUM 



149 



p. 108) of some of the cranial nerve components are summarized (see Fig. 

 71). For the details of these connections the larger text-books of neurology 

 should be consulted. 



1 . General Cutaneous System (part of the general somatic afferent, repre- 

 sented in the V, IX, and X nerves). Chief sensory V nucleus and spinal 

 V nucleus, or gelatinous substance of Rolando of the medulla oblongata. 



AcA 



Fig. 65. A diagram of the sensory components of the cranial nerves of a 

 fish, Menidia. The brain is outlined as seen from the right side with heavy 

 black lines. The general cutaneous nerves (somatic sensory) are outlined 

 with finer lines (unshaded), and all of these fibers are seen to enter a longi- 

 tudinal tract within the brain, the spinal trigeminal tract (sp.V.). The 

 special somatic sensory (acoustic and lateral line) nerves (black) converge 

 within the brain to a special center, theacoustico-lateral area, or tuberculum 

 acusticum (t.a.). The visceral sensory fibers (cross-hatched) likewise all 

 converge to a special center, the lobus vagi (lob.X.). 



Reference letters: b.c.l to b.c.5, gill clefts; br.g.X., branchial ganglia of 

 X nerve; cil.g., ciliary ganglion ; d.l.g. VII., dorsal lateral line ganglion of VII 

 nerve; f.c., fasciculus solitarius; gen.g.VIL, geniculate ganglion of VII 

 nerve; IX., glossopharyngeal nerve; jug.g., jugular ganglion of X nerve; 

 lob.X., lobus vagi (visceral sensory area); n.I., olfactory nerve; n.IL, optic 

 nerve; n.IIL, oculomotor nerve; o.pr., ramus ophthalmicus profundus; pal., 

 palatine branch of VII nerve; r. cut. dors. X., dorsal cutaneous branch of X 

 nerve; r.intest.X., intestinal branch of X nerve; r.lat.ac., ramus lateralis ac- 

 cessorius of VII nerve; r.lat.X., lateral line branch of X nerve; r.oph.sup.V 

 + VIL, superficial ophthalmic branch of V and VII nerves; r.ol., ramus 

 oticus; r.st.X., supratemporal branch of X nerve; r.VII.p-t., pretrematic 

 branch of VII nerve; sp.V., spinal trigeminal tract; La.,- tuberculum acusti- 

 cum (acoustico-lateral area); t.hm., hyomandibular trunk; t.inf., infra- 

 orbital trunk; VIII., auditory nerve; v.l.g.VIL, ventral lateral line gan- 

 glion of VII nerve. 



