7,63 ZOOTOMY. 



by a median groove, continuous with that of the medulla, 

 and lodging the basilar artery. Laterally, the fibres of 

 the pons bend upwards and enter the cerebellum, forming 

 its middle peduncles. 



480. The crura cerebri (cc), two strong diverging bands 

 of white fibres on the ventral surface of the brain, pro- 

 ceeding forwards and outwards from the anterior edge of 

 the pons Varolii. 



481. The cerebral hemispheres (cJi), two large 

 masses which constitute the greater part-of the brain : they 

 are closely applied to one another along their flat inner 

 faces ; broad and somewhat truncated posteriorly (parietal 

 lobes), where they abut against the cerebellum ; pro- 

 duced into a blunt point anteriorly (anterior or frontal 

 lobes, <:./;!) ; and produced downwards into the prominent 

 temporal lobes {c./i'^) which partly overlap the crura 

 cerebri. Where the temporal becomes continuous, ven- 

 trally, with the frontal lobe is a slight angulation, the 

 rudimentary Sylvian fissure. The surface of the hemis- 

 pheres is formed of grey matter, and is smooth except for 

 one or two slight depressions or sulci. 



482. The corpus callosum {c/i.tri), seen, by slightly 

 separating the hemispheres from one another above, as a 

 strong white transverse band, connecting them with one 

 another along the middle third of their length. 



483. The pineal body (pn) and a portion of the optic 

 lobes (o.P-, o.fi) (§§ 517 and 519) are seen on the dorsal 

 surface of the brain, between the cerebrum and cerebellum. 



484. The olfactory lobes {0//), two knob-like bodies 

 of grey matter proceeding forward from the anterior part of 

 the ventral surface of the hemispheres, and connected by a 

 strong white band with the anterior edge of the temporal 

 lobe. They fit into the deep olfactory fossae of the skull. 



