395 
C. J. Sundevall on the Wings of Birds. 
Along the hinder margin of the cubitus and hand the skin 
likewise forms a large, hut firm and hard fold (f,g), in which 
the large wing-feathers are seated. Indeed it is by the con¬ 
siderable development of the feathers that the skin is drawn 
out into a fold which surrounds the roots of the feathers. 
The differences in the length of the different joints of the 
wing will be referred to further on, under the head of the 
Remiges cubitales. 
2. The wing consists of the feathers which clothe the an¬ 
terior extremity, in the skin of which they are seated arranged 
in rows (series) which are parallel to the bones and to the 
posterior margin of each individual joint. 
The feathers are generally directed backwards, so that 
each series covers that lying immediately behind it (or at 
least its root). In general there are about the same number 
of feathers in each series, for they are arranged in quin¬ 
cunx, so that each feather is situated in the middle of an 
interval in the two nearest series. Their points of insertion 
may therefore form rows in three different ways (see figs. 2, 8); 
but the feathers themselves form series only in one way, 
because all those which are placed in the same series are 
nearly of the same size and nature, while those in different 
series most frequently differ considerably from each other 
(see figs. 3, 4, 7, 8). The smallest and softest are placed in 
front ; towards the posterior margin of the wing the feathers 
increase in size and firmness, so that the quill-feathers which 
occupy the posterior margin itself are the largest of all. In 
the enumeration of the series we must therefore necessarily 
begin with the quill-feathers and call them the first series; the 
second, third, &c. follow in order forwards. The foremost 
series are so small and indistinct that one can hardly distin¬ 
guish them unless we proceed in order from the posterior ones. 
In each series we must call those feathers outer (extern se) 
which are placed nearest to the apex of the wing ; and inner 
(internee) those which are situated nearer to the base of the 
wing and the body. As the outermost feathers are always 
the easiest to find, we must commence the ordinal numbers 
(1, 2, 3, &c.) from them. 
