138 



ELEMENTS OF OBNITHOLOGT. 



radiating directly from the summit of the quill. Filo-plumes, 

 or thread-feathers, much resemble hairs, as they are long and 

 very narrow, with a rudimentary vane. Some of these are 

 bristly and called setaceous ; and many Birds have a row of 

 bristles or vibrissce bordering the opening of the mouth or gape, 

 and these are particularly long in the Goatsuckers *. 



Fig. 142. 



b' ■' ' 



Fig. 141. Diagram op a Feather (with only three of its barbs indicated). 

 A. Axis. Q. Quill. E. Eaohis, or shaft, or scapus. W. Vane, vexillum, or 

 pogomum. F. Front half of vane or outer web. H.V. Hinder half of 

 Tane or inner web. B. Three barbs or rami. 6. Barbules or radii. 

 H.B. Hyporaohis or afterahaft. 



Fig. 142. Diagram (afier Nitssch) of parts of Wee. 

 BB. Two barbs in vertical section. 6' *'. Anterior barbules. 6= 4». Poste- 

 rior barbules. e. Barbieels, or barbulets, or hamuli, or booklets. 



Certain down-feathers are called pulviplwmes because the 

 ends of their barbs habitually break up into a fine powder called 

 powder-down, such as may be remarked on Parrots 



The ordinary feathers which clothe the body and hide the 

 down are called contour feathers. Their basal barbs are com- 

 monly soft. 



* See mte, pp. 86, 87. 



