420 dr. j. murie on the sacs [June 16, 



Secretary by Mr. "William Summerbayes, dated Aroa, Venezuela, 

 February 19, 1874: — 



" I have read carfully your Monograph'on the Cracidse : there is no 

 doubt of the correctness of your identification of both Crax dau- 

 bentoni and Pauxi galeata. 



"I have shot specimens of both kinds in this neighbourhood, and 

 compared them diligently with your Latin descriptions, on the accu- 

 racy of which I beg to compliment you. The Crax daubentoni is 

 found here all along the littoral as far as the foot of the mountains 

 (here some 50 or 60 miles inland) ; but as soon as you get among the 

 mountains (and these mines, whence I write, are only some 5 miles 

 up the Sierra and away from the forest which clothes the littoral flat 

 country) you see no more of the C. daubentoni, but numerous speci- 

 mens of Pauxi galeata." 



The following papers were read : — 



1. On the Nature of the Sacs vomited by the Hornbills. 

 By Dr. James Murie., F.L.S. 



[Eeceivecl May 9, 1874.] 



Lapse of time has not erased from my memory the puzzled coun- 

 tenance, not to say blank dismay, of my friend Mr. A. D. Bartlett, 

 on my announcing to him my conclusions respecting the nature of a 

 fig-like envelope containing discoloured grapes, which he suspected 

 had been thrown up by the Wrinkled Hornbill, Buceros corrvga- 

 tus. His alarm for the safety of the bird was converted into mirth 

 at my expense, as a few days afterwards, he returned with a second 

 specimen ejected from the same bird. The latter, it would seem 

 then, was none the worse for losing the interior lining of his stomach, 

 and in the interval had made a new one and got rid of it also. 



I certaudy, at the time, was not prepared for the full extent of 

 the phenomenon. But I felt satisfied from my examination that the 

 sac was not what is ordinarily regarded as a secretion (namely, glan- 

 dular product), but rather was of an epithelial horny kind — the 

 veritable gizzard-lining itself, howsoever reproduced. 



In Mr. Bartlett' s cleverly reasoned paper, P. Z. S. 1869, p. 143, 

 an abstract of my report to him is given. He opposed the notion 

 of the rejected sac being a true gastric lining, and held to its being 

 a secretion provided for and emitted during the breeding-season. 

 He regarded it as of a nature similar in kind to the proventricular 

 secretion of incubating Pigeons, Parrots, &c. As to its greater 

 solidity and gizzard-membrane characters, these he deemed produci- 

 ble by that viscus, and to be analogous to the gastric mouldings of 

 the indigestible pellets cast up by the Raptorial and Insessorial birds. 

 At the discussion on the paper my statement of the sac being the 

 epithelial coating of the gizzard was received incredulously. 



The sac and its contents, and subsequently the viscera of the bird 

 itself, which died shortly after, were consigned to the College-of-Sur- 



