12 ON THE BUESA FABRICII IN BIEDS. 



towards the apex. In a young specimen of Plotus arihinga ( $> ) that I 

 dissected, the appearance and disposition of the parts agreed very well 

 with Prof. Garrod's description. 1 noticed, however, that the opening 

 of the bursa was very slightly constricted by a slight fold of mucous 

 membrane on each side, so that the bursa hardly opened by its entire 

 width into the cloacal chamber. In other respects it showed a strong 

 approximation to the disposition of these parts that I shall presently 

 describe in the Ostrich and its allies. 



In the Herodiones the bursa is large and sac-like, with a small or 

 moderate opening ; its interior surface has no ridges or sulci, but large 

 crypt-like pores collected in patches. In aged birds it seems to disappear, 

 though in a specimen of Abdimia that had lived in the Gardens more 

 than three years it was still present, | inch long, with the opening still 

 unobliterated. 



In Ckawia the bursa is a glandular pyriform sac, about 1 inch in 

 length, with a moderate- sized opening (see fig. 1, p. 8). It seems to 

 disappear entirely in old birds. In a specimen of Cygnus olor it was a 

 large conical sac, 1| inch long, with a wide mouth, but slightly constricted 

 off, and with no large glands. In aged specimens of Fuliyula rufiiia, 

 which had lived sixteen years in the Gardens, and of Tadorna rutila, 

 which was nearly eighteen years old, the bursa had disappeared, in the 

 former having assumed the appearance of a round cord-like ligament, in 

 the latter having become fused with the abdominal aponeurosis. In each 

 case a small pore marked the place of aperture. 



In Pterocles, Goura (in a nine-months-old bird), and PJiaps I have 

 never found any thing more than a small blind pore in the usual place of 

 the opening ; as we know from M. St.-Ange, the bursa disappears very 

 early in Columba livia as well. 



P. Z. S. 1877, In the Galling the bursa has a tubular or pyriform shape, with numerous 

 well-marked alternating ridges and furrows, the latter highly glandular, 

 on its internal surface. These ridges are most marked towards the 

 superior (blind) end, and are formed by the projection into the interior 

 of collections of lymphatic follicles. These last do not open by distinct 

 pores into the cavity of the bursa, but are entirely closed, as shown by 

 Signer Alesi and Leydig. In the process of atrophy the peduncle be- 

 comes sclid ; also the cavity of the bursa becomes shut off from the cloaca 

 and persists in this state for some time. Finally, however, the bursa 

 seems to become reduced to a ligament-like structure, or to become fused 

 with the general aponeurosis. In the Turkey the bursa is a long tubular 

 sac, 2 inches long, with very well marked ridges and sulci. In all a pore 

 marks the opening of the atrophied bursa. In Serpentarius the bursa is 

 a large globular sac, with the glandular area confined to the apical region 

 and a small aperture into the cloaca. In these respects it resembles Otis 

 and Grus. In Forphyrio and Ocydromus it assumes the form of a long, 



