:U 



STRUCTURE AND CLASSIFICATION OF BIRDS 



attached to either the form of the gland or the number and 

 position of the orifices of its ducts. In Syrrhaptes para- 

 doxes, for instance, both of the arrangements figured in the 

 accompanying cuts have been found by BKANDT, who inves- 

 tigated the structure of the bird. In one of them both 

 ducts open close to each other and to the cystic duct on the 

 ascending part of the duodenal loop ; in the other the cystic 

 and hepatic ducts were on opposite sides of the duodenal 

 loop, and in common with each opened a single pancreatic 



FIG. 19. DUODENAL LOOPS OF 

 Rhea americuna. 



hc.e, Jie, bile ducts ; pl,p2, pancreatic 

 ducts. (After GADOW.) 



FIG. 20. DUODENAL 

 LOOP OF Rli. Darwini. 



f-./ii; bile ducts; pl,p2, pan- 

 creatic ducts. (After GADOW.) 



duct. This latter arrangement was found by GADOW in 

 Pterocles. In two species of Rhea the relative positions of 

 the pancreatic and bile ducts were as is shown in the figures. 

 In the owl Photodilus badius I found that the cystic duct 

 opened near to the summit of the ascending arm of the 

 duodenal loop ; below this opened the hepatic duct, and 

 some way below this again, and near together, the two pan- 

 creatic ducts. A good many details upon this subject will 

 be found in GADOW'S paper on the digestive organs of birds. 

 The cloaca of birds is the terminal chamber of the 

 alimentary canal, which also receives the urinary and genital 

 ducts, and is provided with an appendix of unknown function, 



