242 



THE NERVOUS SYSTEM 



From the foregoing account it will be apparent that almost the entire sur- 

 face of the human cerebral hemisphere is formed by neopallium. Of the parts 

 already described only the uncus and adjacent part of the hippocampal gyrus 

 belong to the archipallium. Other superficial portions of the rhinencephalon, 

 such as the olfactory bulb, tract and trigone, and the anterior perforated sub- 

 stance, will be described in connection with the hidden parts of the rhinen- 

 cephalon in Chapter XVII. 



Suprasylvian fissure 



Cerebral hemisphere ^ 

 Cerebellum 

 Postmedian lobule K, 

 Ansiform lobule'r- 

 Parafiocculus\~ 

 Paramedian lobule*' - 

 Flocculus 1 



; Lateral fissure 

 Insula 



Chorioid plexus of 

 fourth ventricle 



XII' 

 XI' 



X // / / / 

 1X''/ VIII; : V 'IV / 

 Olive VII '; VI 

 Trapezoid body 



Pan* 



Rhinal Opic 

 fissure fissure 

 I Mammillary body 

 Hippocampal gyrus 

 Cerebral peduncle 



\ Olfactory bulb 



Lateral olfactory gyrus 



Fig. 173. Lateral view of the sheep's brain. 



The surface form of the cerebral hemisphere of the sheep is illustrated in 

 Figs. 83, 84, and 173. On these figures are indicated the names of the chief 

 sulci and gyri. It will be of interest to note the position of the motor cortex 

 in the sheep as given in Fig. 82. Since this corresponds to the precentral gyrus 

 in man, it will be seen that there is little in the sheep's brain to correspond to the 

 rostral part of the frontal lobe in man. 



