The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1902-03-01
BIRDS GLoRrF1ED REPTILES.

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Ralph Hoffman gave the first of a Sc
ries of lectures recently in the Walker
Building, Massachusetts, Institute OF
Technology. Many children who are
interested in the study were present
in the audience. In this lecture he
went back to the ages before there
were birds and studied the gradual
development from the more primitive
forms. He said in part: VERY few
of the leading facts of geology have
yet become the common property of
the intelligent public. When the
great beds of coal were forming in
the region now occupied by the Ap-
palachian Mountains, the world was
still SO young that the Appalachian
range, though older than the vast
ranges of the Rockies, had not yet
risen from the floor of the sea. The
most highly developed animals on the
earth were fishes and the lower rep
tiles, and there were 10 birds and no
mammals. The plants were for the
most part relatives of our present
ferns, club moss and horsetails. There
were no conspicuous flowers, no bees
or butterflies.
"After the lapse of two more great
periods, but still before the Rockies
had risen from the sea, reptiles had
reached a tremendous development,
and very varied types were living in
the sea, on the earth, and in the air.
Some swan, some walked on two
feet and held to the trees by their
fore limbs /; still others flew through
the air by means of membranes
stretched between their fingers. They
all possessed teeth and the long bony
tail which still characterizes reptile.
In the same rocks in which the first
remains of some of these various rep
tiles are, we find an unusually good
portrait of the first bird. 1t is bird
because it has feathers, but it was at
first considered a reptile because it
has teeth in each jaw, and long,
bony tail to which its tail feathers are
attached in successive pairs.
"The discovery of this extremely
interesting fossil made certain. the
truth which Prof. Huxley's anatom-
mical studies had already led him to
announce that bird is only glori-
fed reptile. From some one branch
in the numerous reptile family a
creature had developed whose scales
had gradually changed into feathers,
SO that he could acquire the power of
flight. When he became clothed with
feathers and his forelege were so mod
flied that he could fly he was no long
er a reptile, but bird, though he
still possessed reptile like characteris-
tics, such as teeth and a bony tail.
The successive steps by which the
birds of the present day were evolved
from this primitive bird are little un-
derstood. We know from the dis
coveries of Prof. March that teeth
persisted after the long bony tail dis
appeared and the fore limbs had be-
come greatly modified, and we know
that just before the glacial period,
which is put at from twenty-five to
fifty thousand years ago, the world
was inhabited by birds which belong
ed to the same families and often of
the same genus, though differing
specifically from those that exist to-
day."
The structure of the present bird
was then considered, that the nature
of its organism might be compared to
that of other vertebrates. The most
obvious difference between bird and
that of almost every other vertebrate
is the power of flight. The modifca-
tion of the fore limbs of bird for
flight has specifically obliterated
their resemblance to the fore limbs of
other vertebrates.
The 1ightness of the bones of a bird,
especially fitting them for flight, is
obtained by the spongy nature of the
bones and by the absence of marrow,
and by the existence of air spaces in
the larger bones when open into air
sacs in the body of the bird. The
shape, moreover, of the birds body
is we'll suited to fight, the breast is
keel-shaped, the wings are attached
to the highest part of the thorax
the arrangement of the internal or
gans by which the lungs and air
spaces are placed high while the
heavy digestive organs, the breast
bone and its heavy muscles below, is
a natural ballasting of the freight
which the bird has to carry through
the air, and gives the body great sta
bility. Still the natural adaptations
of the bird would little avail for fore
ing it through the air if it were not
for the feathers-at once the sail and
propeller of the boat. If a single
feather is examined it will be seen to
consist of stout quill from which
two sets of barbs extend, one on either
side. These barbs are divided again
into arbules, from which extend d
still smaller growths called barbicels
and these are furnished again with
little hooks which serve to hold the
barbicels of the two adjacent barbs
tightly together, and thus present a
strong, almost air-tight, surface.
Without these hooks flight would be
impossible. 1t is significant fact
that the feathers of ostriches and their