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Show 248 NOTE ON MR. BARTLETT's COMMUNICATION. [Feb. 1, separate genera of birds, induces me to believe, that the habit may exist in many other birds and have hitherto been unobserved. In many cases the substance would sink to the bottom of the water, where it would soon decompose; and this may account for its not having been previously noticed. I feel particularly anxious to call the attention of persons keeping Cormorants, and of those persons visiting the haunts of Cormorants, to this habit, as it is highly probable that this bird does the same thing. 7. Note on M r . Bartlett's Communication on the Habits of the Darter. By W . A . F O R B E S , B.A., Prosector to the Society. [Received February 1, 1881.] The specimen put into my hands by Mr. Bartlett is a somewhat broken bag-like sac, which is undoubtedly the shed *' epithelial " coat of the gizzard of the Darter. Where the "epithelium" * is thickest and best developed, at the bottom of the gizzard, the walls have remained intact; but above, where it thins off towards the pyloric and oesophageal openings, they have become broken, so that the sac is widely open here. A small patch of the characteristic hairs {cf. Garrod, P. Z. S. 1876, p. 343, pi. xxviii. fig. 2) of the pyloric part of the gizzard has come away with the epithelium ; these alone would suffice to indicate the bird whence it was derived. The hard epithelium does not extend above the limits of the gizzard : hence none of the mucous coverings of the proventricular gland or oesophagus has been preserved in the ejected specimen. The outer surface of the cast epithelium is smooth and velvety, and exactly similar in appearance to epithelium that has been peeled off the muscular walls of the gizzard artificially. A microscopical examination of a part of the cast epithelium shows that it is quite identical in structure with that of the unshed epithelium of the stomach. I may add that in the stomach of a lately dead example of the species-though not that of the individual which "moulted" its stomach, which is still (February 1) alive and in good health-there is some appearance of a similar " moult " being about to take place, the epithelial layer being easily detached from the subjacent ones, whilst beneath it there is apparently a new, though still very thin, coat of epithelium in course of formation. This appearance is confirmed by sections of the epithelium. 1 I use this term in the same sense as many previous writers have done, as a convenient term for the object in question, without committing myself to any opinion as to its true nature.-W. A. F. |