THE NERVOUS SYSTEM 



1339 



The interpeduncular space is situated in front of, and above, the 

 pons Varolii. It is somewhat diamond-shaped, and its boundaries 

 are as follows : posteriorly, the upper border of the pons ; anteriorly, 

 the optic commissure ; and, laterally, the cms cerebri and optic 

 tract, in this order from behind forwards. The following parts lie 

 within this space, in the order named, from behind forwards : 



Olfactory Bulb 

 Olfactory Tract 



Optic Nerve 



ic Commissure ~¥^^ _ f J 

 Optic Tract -y- ~; '"^''"=" ^' 



Fissure of Sylvius 



_ Broca's Area 



Fifth NeiN 

 Sixth Ner\e TT^" 

 Facial Nei \ e 'C\,<-/' 



ars Intermedia '^^fi^ 



Auditory Nerve'' 



haryngeal Nerve - 



eumogastric Nerve 



inal Accessory Nerve 



Hypoglossal Xeive 



Lcctis Perforatus 

 Anticus 



Tuber Cin-reum 

 and Infundibulum 



Corpus Mammillarc 

 Crus Cerebri 



Locus Perforatus 

 Posticus 



- Pons Varolii 



~.Medulla Oblongata 



Spinal Cord 



Fig. 559. — The Base of the Encephalon, and the Cranial Nerves. 

 I, Frontal Lobe (Orbital Surface) ; 2, Temporal Lobe ; 3, Cerebellum. 



(i) the locus perforatus posticus ; (2) the corpora albicanti?. or 

 mammillaria ; and (3) the tuber cinereum, with the infvmdibulum. 

 (The region which is directly above the interpeduncular space 

 constitutes the third ventricle.) 



The locus perforatus posticus corresponds to the posterior median 

 angle of the diamond-shaped interpeduncular space, and it lies 

 in a deep depression, called the interpeduncular fossa, or fossa Tarini. 



