2 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
the variability in the size and structure of the secondary fibers, the 
recognition of the importance of their ventral ridge, the variation 
of the hook fibers and the constancy of the curved fibers. 
II. THe STRUCTURE OF THE REMIGES 
1. The Structure of Feathers in General 
According to the nomenclature adopted in this paper each feather 
consists of the following parts: (1) Quill or primary quill, (2) 
secondary quills, (3) tertiary fibers (a) hook fibers, (b) curved 
fibers. 
The primary quill is the bearer of all parts of the feather. Its 
shorter proximal part is circular in section and hollow, its longer 
distal part more or less rectangular in section and filled with medul- 
lary air-cells. The primary quill is slightly curved downward and 
inward; on its sides the two feather vanes extend. They lie nearly 
in the same plane. The two vanes are nearly equal in the remiges 
attached to the ulna; distally the outer vanes diminish in breadth 
more rapidly than the inner. The outermost of the hand-remiges 
attached to the metacarpals and phalanges have a broad inner and 
“a comparatively narrow outer vane. The vanes are composed of the 
secondary quills which rise obliquely from the upper part of the 
primary quill, and of the tertiary fibers rising in a similar manner 
from the secondaries. The tertiaries are closely connected with each 
other ; together with the secondary quills they form the apparently 
continuous surface of the feather vane or feather plate. 
2. Material and Methods 
Remiges of the following species were examined: 
PasseErES: Fringilla spinus, Turdus vulgaris, Garrulus glandarius. 
Coracit®: Merops apiaster, Galbula viridis. 
Bucerotes: Buceros monoceros. 
Macrocuires: Cypselus apus, Micropus melba, Macropteryx mystaceus. 
CaprimMu_et: Podargus humeralis, Caprimulgus europeus. 
Srrices: Strix fammea, Bubo maximus, Bubo mexicanus, Nyctea nivea. 
Psittact: Chrysotis @estiva, Sittace cerulea, Stringops habroptilus. 
CucuLi: Cuculus canorus. 
Musopuaci: Turacus albocristatus. 
CoLumBa&: Columba livia. 
TUBINARES: Diomedea exulans. 
ANSERES: Cygnus olor. 
Accipirres: Aquila chrysetus. 
*The systematic arrangement adopted is that of F. E. Beddard, ‘“ The 
structure and classification of Birds.” London, 1808. 
