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Show 306 MR. W. A. FORBES O N T H E [Apr. 1 7, Hooded Crow, Jackdaw, Bittern, Eared Owl (Ohrkauze), Honey - Buzzard, and Coot, showing 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 pudendal), in both sexes of Gallus domesticus and Fulica atra (op. cit. tab. ix. fig. 13, 15, 19, 22-24, and t. x. f. 26). Berthold devotes a special memoir to it1, in which he describes its nervous and vascular supply. Emil Huschke2 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 increases but slowly in comparison with the other parts of the embryo. M. Martin St.-Ange, in his fine paper " Etudes sur l'appareil reproducteur dans les cinq classes des vertebres" 3, 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 Italiana di Scienze Naturali,' 1875, vol. xviii. pp. 133-169 (for calling my attention to which I am indebted to Mr. Salvin), Signor Vincenzo Alesi, of Naples, has published an exhaustive essay on the structure and development of this organ, accompanied by two plates of histological details. His observations have been made on specimens of Meleagris mexicana, Anser cinereus, Anas boschas, Columba livia, Turtur auritus, Corvus monedula. Turdus merula, and Coturnix communis; and he has also examined the cloaca of a female Rhea americana, preserved in the Naples Museum. To his observations on the histological structure and process of atrophy of the bursa I will return after having briefly described the ordinary form and relations of this organ in the birds I have examined. These are 90 in number; and of many of them I have examined more than one specimen. PASSERES. Dacelo gigantea. Oriolus galbula. Colius castanonotus. Garrulax chinensis. Momotus lessonii. Citta thalassina. Merops, sp. Fregilus graculus. Megaleema, sp. Amblyrhamphus holosericeus. Rhamphastos ariel. Cissopis leveriana. Pteroglossus wiedi. „ Trogon puella. CoCCYGOMORPH.E. Cuculus COUOrUS. Podargus cuvieri. Cacomantis, sp. ' Acad. Cres.-Leop. Nova Acta, 1828, xiv. pp. 903-918. '** De Bursas Fabricii origine. Jena**, 1838. 8 Mem. pres Ac. Sc. Franc, par savants divers. 1856, pp. 1-232. |