THE DE^ ELOPMENT OF THE LIVER AND PANCREAS 

 IN AMBLYSTOMA PUNCTATUM 



E. A. BAUMGARTNER 



Institute (if Axatumy, University of M innesota 



FORTY-SIX FIGURES (fOUR PLATES) 



CONTENTS 



I. Introduction 211 



IL The development of the liver, heiiatic ducts and gall-bladder 213 



1. Literature 213 



2. Early development of the liveV 218 



3. Position of the organ during development 223 



4. Development of the biliary apparatus 226 



a. Description of hepatic ducts in the adult 226 



b. Development of the ductus choledochus 230 



c. Development of the major hepatic ducts 232 



d. Development of the minor hepatic ducts 236 



6. Development of the gall-bladder and cystic duct 238 



f. Summary of the development of the biliary apparatus 242 



III. The development of the pancreas and jiancreatic ducts 247 



1. Literature 247 



2. Early development of the pancreas and pancreatic ducts 250 



3. Description of the adult ])ancreas 260 



4. Discussion 261 



IV. General Summary 264 



V. Bibliography 266 



I. INTRODUCTION 



Comparatively little work has been done on the morphology 

 of the biliary and pancreatic duct-systems in vertebrates. The 

 arrangement of these structures has been worked out in the 

 adult forms of a few species but no attempt has been made to 

 correlate these scattered observations or to determine what 

 may be considered the typical arrangement in vertebrates and 

 the major variations which may occur in the various groups 

 of the phylum. The development of these systems is also 



211 



