174 American Quarterly Microscopical Journal. 



Near the external surface of the longitudinal layer, some of the 

 fibers are sent straight between the ducts, and other, apparently 

 special, fibers wind round the two ducts and form a common 

 sphincter. Still other fibers pass around the ducts separately, 

 and thus form special sphincters. The one which belongs to 

 the duct of Wirsung is most marked. 



On the internal surface of the ducts appear very many thin 

 folds. These may originate on any part of the internal surface, 

 and their free edges are always directed toward the orifice of 

 the duct. Not only are the folds very numerous, but they 

 anastomose and apparently give rise to secondary folds, thus 

 making a most complex net work, and the complexity increases 

 toward the orifice. 



The walls of the ducts in their passage through the coats of 

 the intestine, are composed mostly or entirely of areolar tissue. 

 Processes of this tissue extend into the valvular folds spoken 

 of above, and give them a strong framework. 



The ampulla is also furnished with very many folds. These 

 may arise from any part of its surface, and are like the folds in 

 the ducts always directed totiuird its, orifice. The folds anasto- 

 mose, or arise partly from the wall of the ampulla, and partly 

 from the surface of some other fold, or a large fold may give 

 rise to secondary ones. The attachment of these folds and 

 those in the ducts is somewhat similar to that of the valves in 

 the veins (PI. XIV., Fig. i). In cross section the appearance is 

 as if v^ery many anastomosing trobeculae were stretched across 

 the cavity of the ampulla, and the lumen of the terminal part 

 of the ducts which open into it (PI. XIV., Figs. 4, 5). 



In 1727, Duvernoy (9,346) described a reservoir, the ampulla 

 of Vater, between the coats of the duodenum, in the Chatpard* 

 into which emptied the ductus choledochus and the duct of 

 Wirsung. This reservoir was beneath a prominent papilla, and 

 opened at its summit by a single orifice into the lumen of the 

 intestine. " In quo bills et succus pancreaticus invincem permisceri 

 videntur, antequam in cavum intestini effluant.'' In 1802 was pub- 

 lished the description of the same condition in the elephant 

 (39). (See the quotation from Owen, in an earlier part of this 



* I have been unable to decide which one of the cats was meant by Duvernoy. He says of the 

 ChatpardKn question, Catus pardus sen Catus monianus Americanor, implying at least that it 

 was an American felis. But in Cuvier and all other systematic works where Chatpard is defined, 

 it is called Felis Serval, of South Africa and Senegal. 



