ALIMENTARY CANAL 



35 



the so-called bursa Fabricii. Gadow, in a recent work ' upon 

 this region of the alimentary canal, recognises three cham- 

 bers in the cloaca. Above, and separated by a constriction 

 from it, is the coprodeeum, into which the rectum opens ; 

 this is divided by a constriction from the middle chamber, 

 or urodseum, which receives the genital and urinary ducts ; 



b- 



Fig. 21. — Cloaca op Chauna derhianu laid open jpkom in fkont. 



a, rectum ; &, orifices of ureters ; &', genital papillse ; c, fold separating coprodasiim from 

 urodasum ; rf, fold separating urodffium from proctodEeum ; e, opening of /, bursa 

 Pabrioii. (After Forbes.) 



then follows the proctodseum, of which the bursa Fabricii 

 is a diverticulum. 



The bursa Fabricii has been chiefly investigated by 

 FoEBES ^ and Wenckebach.' It is a dorsal diverticulum of 

 the proctodseum, and therefore has nothing to do with the 



' ' Remarks on tlie Cloaca and on the Copulatory Organs of the Amniota,' 

 Phil. Trans, vol. olxxviii. p. 5. 



2 ' On the Bursa Fabricii in Birds,' P. Z. 8. 1877, p. 304. 



' ' De Ontwikkeling en de Bouw der Bursa Fabricii,' Inaug. Diss. Leyden 

 1888. See also E. Eettebet, ' Contribution a I'Etude du Cloaque,' &c., /. de 

 i'Anat. xxi. 1885, p. 369. 



D 2 



