The Journal of 



Comparative Neurology and Psychology 



Volume XVI JANUARY, -r,o6 Number i 



THE STRUCTURE OF THE TELEOSTEAN AND 

 SELACHIAN BRAIN 



BY 



DR. C. U. ARIENS KAPPERS, AMSTERDAM 



With Sixteen Plates 



CONTENTS 



Historical Note i 



Technical Note 5 



Chapter I. The Fore-brain, Prosencephalon or Telencephalon 7 



1. The Fore-brain of the Teleosts 7 



2. The Fore-brain of the Selachians 14 



Chapter II. 'Tween-brain, Diencephalon or Thalamencephalon 20 



/. The 'Tween-brain of llie Teleosts 20 



2. The 'Tween-brain of the Selachians 41 



Chapter III. The Mid-brain, Mesencephalon 53 



1. The Mid-brain of the Teleosts 53 



2. The Mid-brain of the Selachians 62 



Chapter IV. The Hind-brain, Metencephalon ■ . . 68 



1. The Hind-brain of the Teleosts 68 



2. The Hind-brain of the Selachians 88 



Conclusions loi 



HISTORICAL NOTE. 



Even the earliest researches on the brains of fishes, as done by 

 Willis, Collins, Camper, von Haller, Monro and Vicq 

 d'Azyr, treated of the homologies of the different parts of these 

 brains with the brains of mammals, especially man. . These 



