ON THE BUESA FABRICII IN BIRDS. > 



that in " young chickens it was scarcely to be seen ;" as we shall after- 

 wards see, it is developed more in young than adult birds. This fact 

 was first pointed out by Tannenberg in 1789, in his disquisition ' Circa 

 geiiitales partes mascularuin avium ' (Grottingae), and has subsequently 

 been recognized by most authors who have written on the subject (vide 

 Cuvier *, Milne-Edwards t, and Gegenbaur J). Barkow, in a paper 

 ** On the Cloaca of birds " in Meckel's 'Archiv ' , describes its condition 

 in specimens he had examined of the Fowl, Duck, Hooded Crow, Jack- P.Z.S. 1877, 

 daw, Bittern, Eared Owl (Ohrkauze), Honey-Buzzard, and Coot, showing P ! 

 that it is fully developed in young birds, but absent in old ones. He 

 figures the bursa, together with the arteries supplying it (derived from 

 the left pudeudal), in both sexes of Gallus domesticus and Falica atra 

 (op. cit. tab. ix. fig. 13, 15, 19, 22-24, and t. x. f. 26). Berthold devotes 

 a special memoir to it ||, in which he describes its nervous and vascular 

 supply. Emil Huschke^[ describes its development, showing that it 

 arises in the superior part of the cloaca, in which it is differentiated in 

 the embryo of the Fowl from the 8th to the 9th day of incubation, 

 acquiring by degrees a more perfect form, but that after a time it in- 

 creases but slowly in comparison with the other parts of the embryo. 

 M. Martin St.-Ange, in his fine paper " Etudes sur 1'appareil repro- 

 ducteur dans les cinq classes des vertebres " **, figures and describes the 

 bursa in the Common Pigeon. In one adult two-year-old Pigeon he found 

 the interior of the bursa filled up with a sort of calculus, forming a complete 

 cast of its interior. In all others of both sexes, it was reduced to about half 

 its size, and the cavity entirely obliterated. He found that in the egg it was 

 better developed in proportion than other organs, but that after the age 

 of about six months in Pigeons, and eight in Fowls, it began to lose its 

 functional activity, and to become reduced in size. Lastly, in a paper 

 published in the * Atti della Societa Ttaliana di Scienze Naturali,' 1875, 

 vol. xviii. pp. 133-169 (for calling my attention to which I am indebted to 

 Mr. Salvin), Signer Vincenzo Alesi, of Naples, has published an exhaus- 

 tive essay on the structure and development of this organ, accompanied 

 by two plates of histological details. His observations have been made 

 on specimens of Meleayris mexicana, A.nser cinereus, Anas boschas, 

 Columba livia, Turtur auritus, Corvus monedula, Turdus menda, and 

 CoturnLv communis ; and he has also examined the cloaca of a female 

 llhea americana, preserved in the Naples Museum. To his observations 



* Leons d' Anatomic comparee, 2nd ed. vol. viii. p. 276. 



t Physiologic et Anatoraie comparee, vol. viii. p. 514, and vol. vii. p. 347. 



| Vergleichende Anatomic, p. 799, note. 



Archiv, 1829, p. 443 et scq. 



|| Acad. Cses.-Leop. Nova Acta, 1828. xiv. pp. 913-918. 



^| De Bursas Fabricii origine. Jenae, 1838. 



** Mem. pres. Ac. Sc. Frari9. par savants divers, 1856, pp. 1-232, 



