On the Fifth Cubital Remex in Carinatse. 77 



VIII. — Remarks on the Fifth Cubital Remex of the Wing in 

 the Carinatse. By P. L. Sclater, Ph.D., F.R.S., &c. 



One of the most remarkable discoveries in the ptilosis of 

 birds that has been made of late years is that the fifth 

 cubital remex (or fifth secondary) is entirely absent in 

 many groups. This curious fact appears to have been first 

 pointed out by M. Z. Gerbe in 1877, in a communication 

 made to the Zoological Society of France*. 



M. Gerbe writes as follows : — 



" Chez les Rapaces, les Pigeons, les Echassiers et les Pal- 

 mipedes, il y a atrophie complete de Pune des remiges secon- 

 dares, et cette atrophie, qui parait etre originelle, porte 

 invariablement sur la cinquieme. Ses satellites, c'est-a-dire 

 sa couverture superieure et sa couverture inferieure, prennent 

 un deVeloppement normal, et occupent leur place, respective, 

 comme si elles accompagnaient la penne qui fait defaut. 



" Ni les vrais Passereaux, ni les Zygodactyles (les Perro- 

 quets excepte's) ne presentent cette singuliere anoinalie." 



After a lapse of ten years, during which period no one 

 seems to have alluded to the subject, Wray, in the course of 

 his studies of the bird's wing, undertaken during the prepa- 

 ration of specimens for the Index-series in the British Mu- 

 seum of Natural History, rediscovered this phenomenon, and 

 described it, in his valuable paper on the Morphology of 

 the Wings of Birds, as follows f : — 



" The chief, most interesting, and most puzzling modifica- 

 tion of the cubital feathers is that in a great many birds the 

 fifth remex is always undeveloped, its coverts being normally 

 developed and present. This occurs probably in all birds 

 except Fhoznicopterus%, G-allinse, Passeres, and a few Picariae. 

 Up to the present I have never met with a trace of this 



* Bull. Soc. Zool. de France, ii. p. 289 (1877). 



t " On some Points in the Morphology of the Wings of Birds," by 

 Richard S. Wray, Proc. Zool. Soc. 1887, p. 343. I am much indebted to 

 the Publication Committee of the Zoological Society of London for their 

 permission to reproduce Wray's excellent illustrations of this subject. 



% [This inclusion of Phcenicopterw amoug the quincubital birds is an 

 error. As will be shown below, Phcrnicoptenis is aquincubital. — P. L. S.] 



