The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1884-09-20
A MISSING LINK FOUND.
Scientists Rejoice Over the Discovery of an
Egg-Laying Mammal.

Egg-Laying Mammal.
New York Evening Post.
One of the most important discoveries. GER
tainly of this decade, in the annals of biology,
was announced by Professor Moseley at the re-
cent meeting of the British Association for the
Advancement of Science. While the section Of
biology was holding its last session, a dispatch
was received from Professor Liversedge, of
Sidney. saying that Mr.. Caldwell, who had gone
to Australia to study it's peculiar mammalial
fauna, had made the discovery that the Mono
tremes were oviparous, or egg layers. The de-
tails OF this important discovery will be awaited
with great interest, and perhaps to many nat
urallsts the announcement did not cause sur
prise, especially to those who are familiar with
the anatomy of the curious animals in quest on.
scientifically they are known as the Monotremes,
and constitute the group Ornithodelphi that
comprises a single order, Monotreihata,
the lowest IL the great branch of
mammals. The Ornithorhynchide and
the EchidnidB constitute the two families,
and the animals are best known as the duck-bill
and the Splny ant-eater. They are peculiar to
the Australian continent and New Guinea, and
IN their general appearance are the most remark
able OF all mammals When the first specimen
was received in England, many years ago. it
was considered the work of some skilled taxi
dermist and trickster. The creatures attain a
length OF about twenty inches. TIL body is
long and fat, in shape something like that of the
otter, the tur being thick and fine, and generally
of a rich brown hue, with a whitish tint be-
tNoNN AbC hNo4 10 IHC " 1CtlldI III
feature. Instead of a mouth like other mann
mails, there is a perfect bill like that
OF a duck, and seemingly composed of the
same horny substance, and the edges are
provided with transversal plates. Teeth
the duck-bill possesses. though of a novel
KIND, beng placed in the back part of the
mouth. two upon each side, the tops fiat; in
fact, the place of teeth seems to be supplied
functionally by curious horny structures that
form a part of the beak. The tail of the duck
bill is fiat and obtuse, and the feet show many
pecullarities that would seem to connect it with
the birds. They are adapted for swimming, the
toes being webbed, the hinder set being strongly
clawed, while in the fore feet the interdigital
membrane extends beyond them.
In the young females a rudimentary spur is
observed upon the hind legs, that disappears
when the adult form is attained; but in the adult
male there is always found a fiat curved ossicle.
artlculated principally to the tlbia, supporting a
sharp perforated horny spur. The spur connects
with a gland beneath the skin upon the thigh,
and at first appears to be a defensive organ, but
Bennett allowed the spur to laeerate his hand.
and no III effects were noticed, and its functions
are still unknown.
In the internal organization of the duckbill
we ind still other characteristics that call to
mind the birds and reptiles. Thus the sternum
IS keeled, and there are no sternal ossous ribs
as in birds. Another point of remittance is that
the transverse processes of the c~ervical vertebre
are of untogenus formation and remain closely
connected with the remainder of the vertebre
until the animal attains its full growth.
As in the skulls of adult birds the
sutures are entirely obliterated, and, more
remarkably yet, the openings of the urinary
and genital organs and the digestive canal emp
ty into a common cloacla. Finally. it is found
by MI. Caldwell that these animals are ovipar-
GUS, or lay eggs-a fact that shows them to be
closely allied to the reptiles. Yet they are milk
givers, the youngduckbill obtaining its milk sup
ply not from a teat. but from a number of scat
tered pores on a plane surface that lead to the
lacteal ducts. The young probably escape from
the eggs soon after they are laid, as Bennett dis
covered three in a subterranean nest that were
about two inches in length.