14 The Ruffed Grouse 



decreases to fifty millimeters at the back row; the female ruff feathers 

 average shorter. All of the ruff feathers have truncated ends made by 

 the exceptionally long proximal barbs. 



The Humeral Tract bears the scapular feathers, which consist of a 

 band of large feathers extending obliquely across the humerus. Be- 

 giiming at the lower end of the neck they extend to the back edge 

 of the upper ann. 



The Alar Tract consists of all the wing feathers other than those 

 of the humeral tract. Many of these wing feathers are identifiable as 

 individuals and hence are significant taxonomically. The ti-act is 

 composed of primaries, greater primary coverts, middle primary 

 coverts, secondaries, gi-eater secondary coverts, middle secondary 

 coverts, carpal remex, carpal remex coverts, lesser secondary coverts, 

 marginal coverts, alula, alula coverts, carpo-metacai-pal coverts, 

 under gi'cater primary coverts, under middle primary coverts, under 

 lesser primary coverts, under greater secondary coverts, under mid- 

 dle secondary coverts, under lesser secondaiy coverts, and under 

 carpal covert. 



The Femoral Tract covers most of the sides of the thighs with the 

 rows radiating posteriorly from an apex at the anterior end, and the 

 more posterior row curving somewhat dorsally. 



The Crural Tract is divided into two regions, internal and exter- 

 nal, covering the lower leg. The feathers are rather sparse, soft and 

 hairlike, with a plumulaceous aftershaft extending about half their 

 length. 



The Pedal Tract is a continuation of the crural tract onto the tar- 

 sus. The feathers are also similar to the crural feathers, and are even 

 more modified in the same direction. The rachis and calamus are 

 almost entirely gone, and the plumulaceous aftershaft is short. 



The spaces, or bare areas, separating these tracts are described as 

 follows: 



Capital Spaces: The temporal space, in front of and above the ear, 

 is covered by the feathers of the ocular and upper auricular regions 

 of the capital tract. The superciliary space above tlie eye is covered 

 by the feathers above it, while the rictal space posterior to the nos- 

 tril is covered by feathers from the rictal region above it. Over the 

 ramus of the lower mandible is the submalar space, covered by the 

 adjacent feathers of the submalar and interramal regions, while be- 

 hind the culmen the bare frontal space is located. 



