662 



REPORT OF NATIONAL MUSEUM, 1893.- 



[Jnfortunately there is still some doubt as to the exact struetnre of the 

 wing of ArclKvoj^teryx, and it seems probable that it is misrepresented 

 in most text books.* One thing, however is undeniable, there were in 

 this wing 3 well-formed, clawed fingers, and if only 2 of them Avere free, 

 ArcJucopteryx could certainly climb about very readily. 



It seems quite a transition from the long-tailed, toothed Archceopteryx, 

 with its three clawed fingers, to the ordinary birds of to-day, the more 

 that very few of the intermediate stages have been brought to light. 

 Fortunately, however, there is a bird still living, and not uncojnmou, 

 in parts of South America, which goes some distance toward bridging 

 over the gap between gallinule and Archwopteryx. This bird, which 



on account of its many peculiarities, 

 stands quite alone among modern 

 birds, and is looked upon as the sur- 

 vivor of a great grouj) of birds which 

 has become extinct, is Opisthocomns 

 cristatns. From the unpleasant odor 

 of its liesh, acquired from its food of 

 wild arum leaves, the bird is more 

 commonly known as the stink bird, 

 or stinking pheasant, while what 

 Dr. Cones would term its "book" 

 name is Hoactzin or Hoatziu.t 

 The adult birds not only have no claws upon their wings, but their 

 thumbs, even, are so poorly develoi)ed that one would hardly suspect 

 that in the nestlings we have the nearest approach to a quadruped 

 found among existing birds. Mr. J. J. Quelch, who studied them in 

 British Guiana, f tells us that soon after the hatching of the eggs the 

 nestlings begin to crawl about by means of their wings and legs, the 

 well-developed claws on the pollex and index being coustantljnn use for 

 holding and hooking to the surrounding objects (fig. 8). If they are 

 drawn from the nest by means of their legs, they hold on firmly to the 

 twigs both with their bill and wings ; and if the nest be upset by means 

 of a rod liushed uj) from below, they hold on to all objects with which 

 they come in contact by means of bill, feet, and wings, making con- 

 siderable use of the bill, not only to reach objects above them, but also, 

 with the help of the clawed wings, to raise themselves to a higher level. 

 When the parent bird is driven from the nest, owing to the close 

 approach of a boat, then the young birds, uidess they be only quite 

 recently hatched, crawl out of the nests on all fours, and rapidly try to 

 hide in the thicker bush behind. 



WING OF YOUNCi HOACTZIN, OPISTHGCOJICS 

 CRISTATL-S; 



Natural size. 



Mt. No. isftM. r. s. 



* Biological Theories, vii. The Digits in a Bird's Wing: A Study of the Origin 

 and Multiplication of Errors, by C. Herbert Hurst, Ph. D. Natural Science, Octo- 

 ber, 1893, pp. 275-281. Also, The Wing of Archa-opteryx. W, P. Pycraft, M. B. O. U. 

 Natural Science, November and December, 1891, pp. 353-360, 437-148. 



t Given to the bird by Buft'on, who considered it to be the bird mentioned under, 

 that name by the Spanish writer Hernandez. 



X The n)i8 "for 1890, pp. 327-335. 



