72 ZOOTOMY. 



and V'^, ventral ramus of V orbito-nasal nerve : F=S palato-nasal 

 nerve : V"^, maxillary nerve : V^, mandibular nerve : F//^, palatine 

 branch of portio dura: F//^, hyomandibular branch: dy, chorda 

 tympani : V///, auditory nerve : /X, glossopharyngeal nerve : X, vagus : 

 Ajy, branch of glossopharyngeal to hyoid arch : ir. 1, branches of 

 glossopharyngeal and vagus to ist branchial arch : dr. 2, i>r. 3, ir. 4, 

 branches of vagus to 2nd, 3rd, and 4th branchial arches : v, ventral 

 (gastric and cardiac) branch of vagus : /, lateral branch of vagus : 6r, 

 brachial plexus. 



forward continuations of the ventral pyramids of the 

 medulla oblongata. 



174. The thalamencephalon (Figs. 22, 24, 25, i/i), a 

 small division of the brain just anterior to the optic lobes : 

 it consists of two lateral masses of nervous matter, the 

 thalami optici, between which is a space, covered only 

 by pia mater, the thalamocoele or third ventricle {v. 3). 



175. The lobi inferiores (Figs. 23 — 25, It) paired 

 ovoidal bodies on the under surface of the thalamencephalon. 



176. The pituitary body or hypophysis cerebri 

 (Figs. 23 — 25, //), a rounded structure on the ventral 

 surface of the brain, behind the lobi inferiores and attached 

 to a backward prolongation of the thalamencephalon called 

 the infundibulum ; with it is connected anteriorly the 

 median artery formed by the union of the two internal 

 carotids (§ 160). 



177. The saccus vasculosus (Figs. 23 — 25, s.z', s.v'). 

 a thin-walled hollow body, consisting of three lobes, two 

 large and paired, situated one on either side between the 

 pituitary body and the lobi inferiores, and a median azygos 

 lobe lying in the groove between the lobi inferiores. 



178. The prosencephalon (Figs. 22 — 25, c.//), a large 

 transversely elongated mass, in front of the thalamen- 

 cephalon and representing the fused cerebral hemispheres. 



179. The olfactory lobes (Figs. 22 — 25, 7), two long,, 

 nerve-like bodies, given off from the antero-lateral angles 



