OCR Text |
Show 1874.] VOMITED BV. HORNBILLS. 421 geons' Museum, and mounted as preparations. Professor Flower carefully examined and compared the above. In his notice of the object (P. Z. S. 1869, p. 150) he found the stomach possessing its apparent natural coat. Whence, therefore, had the other come ? He confirmed m y statement of the identity in structure of the expelled sac and the internal epithelial layer of the cavity of the gizzard. Both behaved the same to chemical reagents ; microscopical sections of each exhibited a like matrix slightly laminated with scattered nuclei and granules. He failed, however, in either to detect the definite structures ascribed to the inner coat of graniferous birds. There still remain some obscure and hitherto unexplained points connected with the production of these anomalous food-bags, which it is the purport of the present paper to unravel. However incongruously it m a y sound, M r . Bartlett and myself were both right and both wrong-he correct in suspecting the substance to be a periodical regurgitation normally coincident with the process of incubation, in error in believing it to be a secretion derived from the pro-ventriculus or glands opening into the alimentary canal above that. I was justified in its being the epithelial layer of the gizzard, but deceived as to its being cast off through morbid influences. From indubitable evidence on the habits of the wild birds and frequent occurrence of the phenomenon in specimens in the Society's Menagerie, as described by M r . Bartlett, there is validity in assuming that the vomiting of food enclosed in a horny sac is common to Fig. 1. Empty gizzard-sacs ejected by the Subcylindrical Hombill, Buceros subcylindricus, about natural size. |