248 NOTE ON MB. 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 Mr. Bartlett's Communication on the Habits 

 of the Darter. By W. A. Forbes, B.A., Prosector to 

 the Society. 



[Eeceived 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 (c/". 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 con- 

 firmed by sections of the epithelium. 



' 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. 



