The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1867-02-26
POPULAR SCIENCE.

LsPgoIAL REPORT FOR THE EVENING TELEGRAPH'I
Professor Leidy delivered one of the most
interesting of lectures last evening" on the
extinct Mammals of North America" at the
nall OF the University of Pennsylvania. At
an early hour the nall was fully occupied, and
the assemblage was one, as eviuced by the pro-
found attention given during the lecture, fully
able to appreciate the remarks OF the lecturer.
Professor Leidy spoke at great length, and ac-
companied his remarks by Illustrations and
examples of the various subjects under con-
sideratfon, thus conveying lasting impress
sion TO his hearers. Below we give an abstract
of this able leCture:-
That which have chosen as q subject is n
description, primarily, OF the extinct mammals
of North America Some of you may not be
familiar with this torn "mammal;" 1t is one
which we apply to the highest class of animals
including ourselves The term is derived from
the fact that these animals possess organs for
the production OF milk as nutriment and nour-
ishment to their young. II is much better
name that has come into use in the place OF
"quadruped;' for. under this higher cass.of ami
mails there are not only quadrupedal, that is,
having four feet, and man, but there are, in
many instances, reptiles which are classed
under the same term. And under this circum-
stance, the term mammal is more appro-
pirate, inasmuch as 1t covers the whole order of
The higher class of animals, which may and is
subdivided into its several species and genera.
Most mammals are terrestrial; few of them
are aquatic a lesser part are at least aerial, as
for example, the bat. They are warm-b blooded
and generally provided with four eXtremities
n
lungs, which are spongy bodies, contained in
alright cavities of the chest, and separated
from the intestines and cavity of the abdomen
by means OF q muscular partition called the
diaphragm, from the movements of which, in
the cavity containing the lungs, breathing Is
ished, the cavity of the chest Is contracted and
she air expelled from the lungs; when il de-
scends the cavity is enlarged, and the lungs
filled with air. Mammals are generally pro-
Yided with teeth, of two SETS The first is called
tho Temporary" set, or milk set; called tenn
because n n n
early period, and fall out, and are followed by
those which continue in most mammals
through life. Man, am sorry to say, is
ception to this rule, from apparently natural
conditions: They are apt to be lost at much
earlier period in man than is natural in many
other animals
The teeth are divided int three classes:-First,
the lore teeth, or cutting teeth, named the "in-
cisors," as seen in those of the beaver, lower
jaw of the OK, and front teeth Of the lion. The
'icanine,0 we'll marked in the genus cants, as
dogs, wolves, etc. The canine teeth are some-
times called eye-teeth-are long, pointed and
well adapted to pierce. The third class of teeth
are somewhat peculiar, and are called grind
ers,' and in scientific language are known as
"molars." These the three kinds of teeth
which shall refer to in speaking ofthe various
mammals.
flesh, the moar teeth, although so called in
those ORDERS are not properly grinders, because
points adapted 10 penetrate and cut into the
flesh. 1t is only in herbtferous animals tnat we
find these molar teeth adapted to grinding and
masticating. Mammals we divide into orders,
and nearly all the orders now existing are
The exceptions being in the order of primdteS,
including man and apes, chetr0pterd, the bats,
some OF the fausctcaPGt, and also some OF the
of the orders of these animals. We have on
the other hand, the representation of the order
eaters We have, too, the thick skinned ami
NAL, with the subdivision of the order
gigantic of existing quadrupeds. We
have in one Of these subdivided orders of
this genus, the thick S-slIinned, as the hog. We
have the order of Illuminating animals, from
TIlT,ltrdnts, the title given by that greatest OF
have a complicated stomach of four cavities so
disposed as to allow of rumination or the act
subjected to mastication. In this order are such
animals the OK and sheep. There were also
the gnawing animals, as the rOdentta, which
species. The sloth-like animals, applying to
the order of edentates, the word signifying
without teeth" although some of these ami
mails have teeth, but incomplete yet there are
others which are entirely without teeth. Aud
the last order of extinct mammals, represented
by analogy in their forms to living orders, is
that of The cetaceOuS, or Whale-llke animals.
The whales are properly mammals; they
of the striking characteristics exhibited in other
classes of mammals.
They have the same organs for the nourish-
ment of the young the highest in the order;
and breathe through the gills,as fishes, yet they
have lungs in the cavities of the chest, and, as
in man. separated from the intestines by means
of the diaphragm. And though in their struc-
habits, yet they are true mammals.
Now we will turn to another part of our sub
ject, and examine the geological formation of
the earth, for the purpose of ascertaining where
these forms of extinct mammals have been
found. (Here the Professor exhibited a large
diagram, showing the formation of the earth,
the various strata of rocks explaining the diff
ferent formations, giving their scientific divi-
siOns and subdivisions, with a view to ascer-
tanning the proof of extinct species of animals,
by the discovery OF certain parts of their
structure.)
Upon the surface of the upper strata of rock
we have soil. This soil may be ploughed field.
If we were walking across this field and should
observe foot tracks, we should recognize 1t as a
positive fact that somebody had passed over the
field before we had. None would deny that q
footprints before him. Now If, in passing over
this field, he should pick up from among the
burrows an arrowhead of stone, or q bone, he
would recognize them, and look upon them as
land.
IT. upon:dgging into the rock, beneath the
strata OF sandstone, he found bone or shell
or tooth which was quite different from any in
the vicinity, he would look upon them as
remains of animals which had long disap
peared and had become extinct. If in second
stratum of rock he found shells and bones
differing from those above, he would conjecture
that they belonged to another race entirely dis
tinct, which had preceded the race of animals
that mad existed in the formation of the differ
ent strata above And so in succession, If
he would find fossils in the various layers of
rocks, he would recognize them as different
from those above. And If he should see fossils
IN inclined rocks he would know them to be
the remains of animals that had existed long
anterior to all those he found In the regular
succession of strata; because IT Is evident
that these rocks, inclining upon the others, had
been rent and thrown up by some great up.
1erent portions OF the earth and consequently
such rocks by this force would be lifted from