ALIMENTARY CANAL, ETC., OF AMIURUS CATUS. 413 



As early as 1827, Weber 1 described the presence of a duct in 

 'yprinus carjrio running parallel to the ductus choledoclras and 

 originating in the central lobe of the liver ; as he found no distinct 

 pancreas, he regarded the portion of liver mentioned as performing its 

 function, since it differed from the rest of the liver in color, form, 

 attachment to the intestine, and division into lobules. 



A little later Brandt and Ratzeburg described a glandular body 

 in Silurus glanis, much like the liver and extended behind it envelop- 

 ing the ductus choledochus. This organ, they believe, to be the 

 pancreas. 



Cuvier- maintained that the pyloric coeca were glandular organs 

 performing the functions of a pancreas. 



Alessandrini 3 discovered a pancreas in the pike and the sturgeon, 

 the latter having also a complicated pyloric appendage. 



Johannes Midler 4 and Steller separately showed that in some fishes 

 both pancreas and pyloric coeca may coexist, while in others the former, 

 as a well developed organ, may occur in the absence of the latter. 

 The genus Lota was mentioned as an example of the first-named 

 condition and Silurus and Murmna of the latter condition. 



The organ described as the pancreas in the pike by Weber, Cuvier 

 believed to be part of the liver proper, and added that he had seen 

 an excretory duct in a very large Silurus, opening into the midgut 

 and terminating in the right lobe of the liver. This duct he re- 

 garded as an hepato-intestinal duct. 



The view that the organ generally regarded as the liver in fishes 

 is divided into a bile-secreting portion and a trypsin-secreting portion 

 was held by Stannius. 



Bernard 5 in 1856 described a pancreas present in the intestines of 

 an unknown specimen of fish and also in the turbot. In those fishes 

 in which a pancreas was not observed, Bernard supposed that its 

 functions were performed by the mucous coats of the midgut. 



Nothing important was added to these observations until 1873, 

 when Legouis determined the presence of a pancreas in all fishes 

 studied by him. His work has been the most important yet as lay- 



1 Meckel's Archiv, 1827. 



2 Cuvier et Valenciennes. Histoire Naturelle des Poissons, Paris, 1828. 



3 Novi Comnien. Acad. Scien. Institut, Bonon, 1836, Tome It. 

 * MUUer's Archiv, 1840, page 132. 



5 Lecons de Physiologie experimentale. Tome II., page 478. 



6 Annales des Sciences Naturelles, 1873. 



