San Antonio daily light. [volume] (San Antonio, Tex.) 1886-1907, 1895-04-21
THE SKIN OF ANIMALS.
In Some it is a Defensive Armor
Made of Horn and Bone,

Made of Horn and Bone,
From the Washington Star.
Osteologist LUCAS, of the Nat
Ional Museum, is preparing a new
exhibit, which is designed to show
the various notifications OF the
skin OF animals.
To begin with, there will be a
queer sort OF alligator from South
America, called the "jacari." 1t
is quite different from any alliga-
tor of North America, belonging
to peculiar genus that has bony
plates Oh the under side as we'll as
on the upper side of the body.
Thisis a distinguishing mark Of
the tribe, such alligators as are
known elsewhere in the world
being thus armored only on their
backs. The armor plates of the
alligator are Of true bone-the
same sort OF bone as that of the
animals skeleton.
II you will examine the skin on
the back Of your hand you will find
that it is corrugated and broken up
with fine lines in such a way that
you can easily imagine its texture
transformed by eXaggeration into
scales. Now, you have only to
gaze upon an armadillo in order to
see such modification of the skin.
In Africa is found a yet more curl
Gus animal, called the "manis
macrura," which is the most scaly
Of all scaly beasts. From the tip
Of its nose to the end of very long
tail it is clad in big horny scales
that overlap one another. When
alarmed it curls itself up into a
tight little ball, and the scales
being quite sharp, it is pretty safe
against attack. In this case also
the scales are only modified skin.
1t is worth mentioning, by the
way, that the manis macrura pos
sesses a greater number of verte-
brae than any other mammal.
Mr.. Lucas will show, in the same
case with the jacari and the arma.
dillo, a "scheltopusic." This is a
lizard from Sicily. The casual OBJ.
server would take it for a snake,
its legs being rudimentary and
concealed beneath its skin. The
entire body Of the reptile is covered
with little plates of bone. As in
the case of the alligator above de-
scribed, the bOny plates of the liz.
ard are merely modified skin.
The same is true of the very remark
able "boX fish" of the West Indies,
which is clad in a complete armor
Of siX.sided plates of bone, which
are fastened to the skull and to the
bases Of the dorsal and anal fms.
An odd point about this fish is
that it can not bend its body at
all, the veatebrae, save only three
or four near the tail, being fused
together. Thus the backbone is a
solid rod.
The scales of the aramadillo are
of bone, covered with horn, the
bone and the horn corresponding,
respe ctively, to the true skin and
the epidermis of human being or
other animal. Bony plates and
spines are notifications of the true
skin, while horn is modified epider-
mis-. Human beings sometimes
develop horns, but they are alb
normal grOwths. Another queer
fish that will be shown in connec-
tion with this exhibit is the ''globe
fish," which is found in waters of
the coast OF South Carolina. 1t is
clad in an armor of interlocked
spines, which are made to stand
erect at the will of the animal,
thus rendering the latter an unat-
tractive morSel to swallow. In a
world like this, where every living
creature is the prey and food of
others, animals are often obliged
to put on coats of mail IL they
would survive.
Mr.. Lucas will make fur and
feathers a part of the exhibit.
Feathers and hair are the same
thing, differently modified, of
course. A stuffed and fretful porcu-
pine will illustrate the fact that
mammals as we'll as birds have
quilts. This is true OF several
species of mammals, notably the
European hedgehog, which is a
disagreeable creature to handle
without gloves. A while ago there
were couple of porcupines in the
geological collection in the rear of
Smithsonian Institution. One of
them assaulted an attendant, and
stuck about thirty OF itsl quilts
into his legs. He-the attendant,
not the porcupine-told a writer
for the "Star" yesterday that the
quilts came out OF the porcupine
much more easily than they came
out of his leg.
Porosity of Glass.
Some interesting experiments