OCR Text |
Show 1889.] MR. P. L. SCLATER ON OPISTHOCOMUS CRISTATUS. 57 February 19, 1889. Dr. St. George Mivart, F.R.S., Vice-President, in the Chair. Mr. Sclater exhibited a series of specimens of the eggs and chicks of the Hoatzin (Opisthocomus cristatus), obtained by Mr. J. J. Quelch, of the Museum, Georgetown, Demerara, on the Canje Creek, Berbice River, in 1888, and made the following remarks :- In 1884 Mr. E. M . Brigham, in a paper read before the Chicago Academy of Sciences (see ' Ibis,' 1885, p. 118), made some extraordinary statements about the condition of the wings in the embryo of the Hoatzin (Opisthocomus cristatus), as observed by him while making " Einbryological Studies " in the island of Marajo, on the Lower Amazons. Mr. Brigham stated that during the latter portion of the period of incubation, and for several days after hatching, the fore feet, toes, and claws of this bird had the appearance of feet, and afterwards evolved into wings ; he consequently called the Opisthocomus a " quadruped bird." When my son went to British Guiana in 1886 I called his special attention to this subject, and requested him to get me specimens of the eggs and young birds of Opisthocomus for examination. Want of time prevented him from effecting this (see ** Ibis,' 1887, p. 319) ; and I consequently applied to Mr. Quelch, the curator of the Georgetown Museum, to aid me in this matter, and obtained for him from the Royal Society's Donation Fund the sum of £5, to enable him to undertake the necessary expedition. Mr. Quelch most kindly acceded to m y request, and made two expeditions to the Canje Creek of the Berbice River, in 1888, for the purpose. When he first went there, in March last year, he found the birds abundant, but only just beginning to lay (see • Ibis,' 1888, p. 378). Mr. Quelch consequently made a second expedition, and writing from the Berbice Hotel on May 24th of that year, announced that he had made a pretty complete collection, consisting of twelve adult birds, a dozen or more of nestlings of different ages, besides chicks and eggs. This series of specimens reached me safely last autumn, and has been placed in the hands of our Prosector, Mr. F. E. Beddard, for examination. Mr. Beddard is now preparing a paper for ' The Ibis' on this interesting subject. In the meanwhile I exhibit some of Mr. Quelch's specimens of the young and eggs. The young, it will be observed, are peculiar for having the fore limbs well developed and the claws on the pollex and index both present and of large size. According to a paper by Dr. C. G. Young, recently published in the 'Notes from the Leyden Museum ' (vol. x. July 1888, p. 169, pi. 8), they would seem to use these claws for the purpose of leaving the nest when young and climbing about the branches of the trees. There is thus some foundation for Mr. Brigham's story of the " quadruped bird." |