AUTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, DECEMBER 28 



THE DEVELOPMENT OF THE CRANIAL SYMPATHETIC 

 GANGLIA IN THE RAT 



FRED W. STEWART 



Department of Histology and Embryology, Cornell University, Ithaca, New York 



THIRTY-SIX FIGURES 



CONTENTS 



Introduction 163 



Historical 164 



Material and methods 171 



Observations 



Forward growth of the sympathetic of the cervical region 172 



Vagus portion of the sympathetic 174 



Glossopharyngeus portion of the sympathetic 188 



Facialis portion of the sympathetic 195 



Trigeminal portion of the sympathetic 200 



The ganglion cells of the nervus terminalis 201 



Summary 205 



INTRODUCTION 



The developmental history of sympathetic ganglia, associated 

 with the various cranial nerves, has hitherto been little studied. 

 The attention of embryologists has been almost entirely directed 

 toward determining the origin of the larger sympathetic gangli- 

 onic masses, namely, the ciliary, sphenopalatine, otic, and sub- 

 maxillary ganglia. The general consensus of opinion would seem 

 to assign to the last three ganglia a trigeminus origin, at least 

 in mammals. Investigation of the origin of the ciliary ganglion 

 has been productive of varying results. Practically nothing is 

 known concerning the development of sympathetic ganglia re- 

 lated to the more caudally situated cranial nerves, the facialis, 

 glossopharyngeus, and vagus. The tendency is to consider 

 definitive sympathetic ganglionic masses absent. The neural 

 crest, however, is continuous throughout the region of the cranial 



163 



