THE FOKE-BBAIN 



615 



This research was continued by Fasola with a view to 

 determining the physiological value of the cornu Ammonis, which 

 is a special part of the cerebral cortex. Fasola showed that in 

 dogs the cornu Ammonis is concerned not only with the olfactory 

 sense, but also with vision and hearing. It is a part of the brain 

 in which a partial fusion of different sensory centres takes place, 

 such as we showed in the parietal lobe of dogs. 



H. Munk records the case of a dog which became blind after 

 the destruction of the occipital cortex, and which seemed to have 

 also lost the sense of smell. On making sections it was found 



PIG. 305. Internal surface of left hemisphere of same infant. 



that the entire hippocampus on both sides was transformed into 

 a thin-walled cyst. 



. Hughlings Jackson and Beevor observed a case of tumour of 

 the right hippocampal convolution, in which the patient had 

 subjective olfactory sensations. 



Flechsig, too, by investigating the myelination of the fibres 

 during development, succeeded in mapping out a cortical field in 

 the hippocampal region which he held, in agreement with these 

 few physiological and clinical observations, to represent the 

 olfactory centre (Figs. 304, 305). It is probable, however, from 

 anatomical facts that this centre is not entirely confined to the 

 hippocampal region. The researches of Meynert, Brown, Golgi, 

 and others show that in the human brain the olfactory tract has 

 three roots, the outer of which ends in the hippocampal convolution, 



