HEAD AND NECK OF THE HORSE 



183 



fissures (fissur?e) and sulci, which separate winding ridges referred to 

 generally as convolutions (gyri). The shallower sulci and the smaller 

 convolutions are of little anatomical importance, but the deeper grooves 

 and the main convolutions must be regarded as of morphological 

 moment. A landmark of fundamental importance is the undulating 

 rhinal fissure (fissura rhinalis) that divides the rhinence'phalon'^ form 

 the much larger and more dorsal pallium'- of the hemisphere. 



Ectolateral sulcus 

 I 

 Rhinal fissure. 



Suprasylvian sulcus. 



1 Ectosylvian sulcus. 



Cruciate sulcus. 



Cerebellum 



Brachium pontis.-^ 



Choroid plexus. - -p 



1st cervical nerve 



, Orbital sulcus. 



Olfactory bulb. 

 Olfactory tract. 



( \ \ \ ^ \ Lateral olfactory stria. 



', \ 1 \ \ Rhinal fissure. 



\ \ I 



^ V Lateral fissure (Sylvian). 



Medulla oblongata 



I ' Hypophysis. 

 \ III. 

 I Cerebral peduncle. 



Piriform lobe. 

 Infundibulum. 



VL Pons. 



Fig. 85. — Lateral aspect of the brain. The Eoman numerals refer to the 

 cerebral nerves. 



Pallium. Dorso-lateral surface. — The dorso-lateral surface of the 

 pallium is covered by convolutions that, for the most part, rise tier above 

 tier, and are arranged in a curved manner relative to a fissure of con- 

 siderable depth, the lateral cerebral fissure (fissura cerebri lateralis) or 

 fissure of Sylvius. ^ This occurs on a level with the deep transverse 

 depression that forms the anterior boundary of the most prominent and 



1 pt's (rhis) [Gr.], the nose. eyKd(pa\oi (encephalos) [Gr.], the brain. 



'^ Pallium [L.], mantle. 



3 Franciscus Sylvius (Francois Dubois), French anatomist, 1614-1672. 



