THE DEVELOPMENT OF THE PARAPHYSIS AND 

 PINEAL REGION IN REPTILIA 



JOHN WARREN 



From the Anatomical Department, Harvard Medical School 



THIRTY-NINE FIGURES 

 THIRTEEN PLATES 



CONTENTS 



Introduction 313 



Description 314 



Lacertilia 314 



Chrysemys marginata 326 



Discussion 332 



Subdivisions of fore brain 332 



Paraphysal arch and paraphysis 347 



Velum and post velar arch 351 



Choroid plexuses 357 



Commissures 360 



Superior commissure 362 



Posterior commissure 363 



Epiphysis and pineal eye 365 



Summary and conclusion 368 



Bibliography 371 



INTRODUCTION 



The term 'pineal region' is used here in the same sense in 

 which it was introduced by Minot in the morphology of this 

 region in Acanthias, and refers to those structures arising from 

 the roof of the prosencephalon and diencephalon, particularly the 

 paraphysis, velum transversum, epiphysis, superior and poster- 

 ior commissures and the choroid plexuses. This paper is the 

 fifth one on this region based on studies from material in the Har- 

 vard Embryological Collection and the observations were made 



THE AMERICAN JOURNAL OP ANATOMY, VOL. 11, NO. 4 

 MAY, 1911 



313 



