New-York tribune., 1899-06-04
THE CLOTHING OF BIRDS
STRUCTURE. COLOR AND USES OF
FEATHERS.
From The Edinburgh Scotsman.

definition Of a bird one might say that II Is
"feathered animal" In the possession OF .eatn, ttn,
ers birds are quite unique. and there is no pro
without feathers Even the ancient Dli'l5 l"uf"
az fossils with teeth and long -jonted, lizard-
like tails were feathered. The possesS'oh VI
feathers. moreover, Is closely connected WIN
the other characteristics that mark off the class
of birds SO distinctly from their nearest reia-
tives. To many minds IL is diihcult 10 Deie'e
or imagine that birds are the oescehdanls VI
reptiles A reptile is cold-blooded anc unaDle
to fly A bird is the hottest -blooded or all am
mails The change has been due In part 10 .ne
development Of feathers. That teathets are
non conductors OF heat is a fact taken adNah-
tage Of by every who has used an eider
down quilt rhe increased temperature has
helped to make the life Of birds quicker ana
more intense. to make them "giorihed rept,eS,
as they have been called. The power oil nisn'
has also helped and ii Is feathers that Wade
flight possible
1t is true that in past geological ages there
were flying reptiles without feathers known dS
rterodlctyls But these seem not TO have been
the ancestors of birGs. Whether owing TO the
want of feathers or to inability to stand upright
the experiment did hot succeed ana the p'ero-
dactyls have left no descendant. but aholher
group of reptiles developed feathers and became
the ancestors of n class that was To dispute
with the mammalia the highest rank in the or
ganic world. Feathers help flight not only nd-
rectly by keeping up the body temperature, but
directly by their structure. Birds OF the duck
family, that moult all the chief wing feathers
at once are unable to fly until new set mas
feathers. Placed above Immediate want by their
higher organization. they have been enabled TO
give a considerable share Of their attention to
matters beyond the bare necessities Of existence.
The greater development of the brain has made
POSSIBLE the cultivation Of an aesthetic sense.
The feathers therefore-amost the only parts
exposed to view-haYc been used for decorative
purposes In this the birds have set an exam
Pile that they have since had reason to regret
TO examine more closely the various uses of
feathers it will be necessary to consider the
structure Of feathers, their various forms and
colOrS, and their distribution over tne surface
OF the body.
The appearance of an ordinary wing or tail
feather is familiar to all 1t consists or mol
low transparent quill, continued as a solid ana
opaque shaft frnged with barbs These barbs
in their turn bear barbues, and these again
give off barbices. 1t is the barbules and bar
bicels that give the feather its value in flying
and steering II the barbs were allowed 70
stream out Independently. the feather would
offer little resistance to the air. and would
therefore be useless as a lever to prOpel or
guide the bird in flight. As every one has OBJ
served however the Darbs Of qul-feathers cling
together. This is effected by means Of the bar
bules and barbcols. Each barb carries two
kinds of barbules, each kind confined to one side
OF the barb. Those on the side toward the base
OF the feather have dOubled-in margins 10
which cling the hooked barbicels of the adjoin-
ing barb As the barbules cross each other at
a considerable angle. each of the hook-bearinS
set is attached To about five Of the doubled-in
set. and each of these is held by the same num-
Der or hooks belonging 10 ulHefent DdTDuleS ol
the next barb. The wing and tail feathers OF
the type described are clas jed with the ordinary
feathers that form TIE general covering of the
tJdy as contour feathers"
OF the remaining varieties the chief are those
known downs, and hlOpumes or thread
feathers. Many feathers appear double. owing
to the presence Of supplementary shaft spring
ing from the same quill and bearing barbS ana
barbules, but no barbicels This "after-shaft.
ii is called. may be equal in size 10 the main
shaft as in the caSSOwary and emu or II may
be small or absent as in the ostrich. II is best
developed in downs and in small contour
feathers. The downs owe their loose appearance
to the absence Of the booklets that bind together
some, though not all, Of the contour feathers.
In some downs all the barbs start from one
point Filopumes are the result Of the sup
preston Of the barbs.
Flying birds have always. in their adult state.
feathers with interocked barbs. Downs and
foplumes found only under the contour
feathers, or associated with them. In running
birds structure that would offer much re-
Sistance to the air would be a hindrance rather
than an advantage. This is probably the
planation Of the loose flowing contour feathers
Of the ostrich and i'm the bare spines Of the
cassowarys wings So in the penguin. which
uses its wings under water. the feathers have
been reduced almost To scales. and lie close TO
the body.
In the same birds we find an unusual dstribu-
ton Of feathers, due apparently to the same
causes The contour feathers, on other parts of
the body as we'll the wings and tail. appear TO
be of some in flight II would therefore be
more advantageous Cor flying bird To have its
feathers in well-defned patches, capable Of nde-
pendent movement. than To have them spread
equally over the whole body We find accord
ngly that very few birds have a continuous COW
ering of feathers. In the penguin. the ostrich
and the apteryx, however the feathers are
equally distributed. and thus offer less resist
anCe to the water or air.
The colors Of feathers produced in several
ways They may be due to the presence OF pig
ment or 10 structure. or to both Red black and
always Dlgmpntal COlOrS.