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Anatomy of the Nervous System 



thalamus and others go to the cerebral cortex, while many of 

 those ending in it are tertiary olfactory fibres from the various 

 secondary areas which have just been described. Many of 

 the latter, however, pass on to end in the hippocampus. 

 Ascending fibres from centres lower in the brain also reach 

 the septum. The medial olfactory stria sends many of its 

 fibres into this region. 



Connecting the septum with the amygdala and the pyri- 

 form cortex is a thick strip of gray matter mingled with a 

 diffuse tract of white fibres, the whole being known as the 



form bulb 



Trolf.hypthS 



Fig. 4 



Diagram of some of the principal olfactory pathways in the rat, 

 from Herrick, Introduction to Neurology. 



The chief connections of the medial and intermediate olfactory 

 tracts are indicated; those of the lateral olfactory tract are omitted: 

 c. mam., corpus mamillare; col. jorn., columna fornicis; com. ant., com- 

 missura anterior; com. hip., commissura hippocampi; com. post., com- 

 missura posterior; form, bulb., formatio bulbaris; /. retr., fasciculus retro- 

 flexus of Meynert; hab., habenula; h. pc, hippocampus praecommis- 

 suralis; h. sc, hippocampus supracommissuralis (indusium griseum); 

 n. ant., nucleus anterior thalami; n. olf. ant., nucleus olfactorius anterior; 

 n. pop., nucleus praeopticus (ganglion opticum basale); S., septum; 

 str. med., stria medullaris thalami; tr. mam. th., tractus mamillo-thala- 

 micus (Vicq d'Azyri); tr. olf. hypth., tractus olfacto-hypothalamicus or 

 basal olfactory tract; tr. olf. tegm., tractus olfacto-tegmentalis; tub. f. 

 dent., tuberculum fasciae dentatae (hippocampus postcommissuralis); 

 tub. olf., tuberculum olfactorium. 



