( 313 ) 



XVI. — The True Shape, Relations, and Structure of the Alimentary Viscera of 

 the Porpoise (Phoccena communis), as displayed by the Formal Method. (With 

 Lantern Demonstration of their Microscopic Structure.) By David Hepburn, 

 M.D., F.RS.E., Lecturer on Regional Anatomy, and David Waterston, M.A., 

 M.D., F.R.S.E., Demonstrator of Anatomy, University of Edinburgh. (With 

 Three Plates.) 



(Read July 15, 1901.) 



TABLE OF CONTENTS. 



Introductory .... 

 Method of Preparation . 

 External Appearances . 

 Cavity of Abdomen 

 Peritoneal Folds and Reflections 

 Absence of Foramen of Winslow 

 Stomach— First Compartment 

 „ Second „ 



„ Third „ 



' „ Fourth ,, 



Pylorus 



PAGE 



313 

 313 

 314 

 315 

 315 

 316 

 317 

 319 

 321 

 322 

 324 



Duodenum 324 



Bile Duct 324 



Pancreatic Duct 324 



Intestine 325 



Pancreas 326 



Liver 326 



Spleen 319, 327 



Conclusions 327 



Literature . . 328 



Explanation of Figures 329 



Introductory. — Among the toothed whales (Odontoceti) the porpoise is the best- 

 known representative of those members of the genus Delphinus or true dolphins which 

 present a rounded muzzle as distinguished from a snout, and consequently it has 

 already frequently been subjected to anatomical examination of a more or less detailed 

 character. As in the case of all the Cetacea, however, the rapidity with which decom- 

 position affects the various tissues and organs has hitherto proved a barrier to a 

 prolonged and systematic examination of them, while, even under the most favourable 

 conditions, the increasing putridity of the carcase has seriously militated against the 

 recording of accurate observations. 



Accordingly, when a porpoise, which had been captured in some fishing nets twenty- 

 four hours previously, came into our possession last December, we took immediate steps 

 for its perfect preservation, so that its dissection might be conducted at leisure under 

 conditions of comfort as well as accuracy, and its various tissues "fixed" for reliable 

 examination by the microscope. 



Method of Preparation. — We therefore first recorded the measurements and 

 external appearances of the animal, and then, having placed it upon its back in such a 

 way as to remove all pressure from its dorsal fin, we opened a comparatively small vessel 

 on its ventral aspect between the anus and the tail. Into thin vessel — a small vein 



TRANS. ROY. SOC. EDIN., VOL. XL. PART II. (NO. 16). 3 a 



