The Hillsborough recorder. [volume] (Hillsborough, N.C.) 1820-1879, 1859-06-22
For Ii. Hlllshorough Recorder.
DEN Al SCIEN +.
COMPARATIVE ANATOMY OF The TEETH.

made one of importance in the Baltimore
College OF Dental Surgery, and very proper
" so. as it is necessary in order TO get a
scientific knowledge Of the profession. that
we should notice yery attentiye'y the origin
and development of similar organs IN the IN,
ferior classes Of animals. And so with all
the other organs OF the human body, much
may be obtained by comparison which is
essential to the full understanding of the
structure and functions of the various parts
endowed with vitality.
Cuyier and Owen, with many others, have
shown that the teeth OF all ANIMALS obey
the same fixed aud immutable law OF hnlitd.
ton in their form, size, structure, junction
and duration-in a word, that all the essen
tial elements Of their organization are ODE.
dent to and are governed by the same gen.
eral laws. The teeth are now considered
the most secure basis by which we may cias-
sify the animal kingdom; for every class Of
animals having the form uf their teeth diff
fering from that OF any other class, We may
readily perceive the distinction and obtain a
foundation Of classification superior 70 any
other, which, by the great durability OF these
organs, and their superior resistance to de-
composition, the geologst is furnished with
a Key by which he may unlock the history
of the past, and testify, not simply OF the
existence of animals long since extinct, but
accurately classify aud faithfully describe
their habits, food, and other peculiarltes.
The ertem of tie dental organs proper
seems TO be limited to the yertebrated di.
vision Of the animal kingdom, OF confined to
those possessing spine. In the invertebra-
ted, instead of true teeth, the parts answer
ing their purposes are rather horny or cal
eafeous indurations. The mammaia, or
animals that suckie their young, with few
exceptions, have teeth, and, according 10
several French writers, several ANIMALS
which seem to be destitdte OF them were
found to possess them during part " their
lives. Teeth, in the human subject, nata,
rally consists OF three parts. neck, crown
and root; but this division does not apply to
all classes Of mammalia, Tor the insclssors OF
the rodentia and the tusks OF the elephant
are covered with enamel over the whole ex-
tent, and therefore are said to be without
roots. This distinction IS said not TO be
good, since portions Of these teeth are i'm
bodied in aveolar cavities like human teeth
The teeth of mammalia are divided into
sssimple, compound and mixed" The sim
Die are those which are covered with a
smooth and even layer OF enamel through
out.
The compound teeth are ike several teeth
Joined together, and the cavity OF the COM
pound tooth has as many parts and subdi-
visions as there are parts joined together.
Fancy molar tooth with its roots covered
with enamel. and you have good idea Of
the compound teeth OF some ANIMALS.
IN the mammalia there are also two kinds
OF teeth, the deeiduous or milk teeth and the
permanent. The number of teeth in these
vary very much. The largest number being
one hundred and ninety, AMI Is only found IN
the dolphin.
The teeth Of other mammalia differ most
especially from those Of man in the shape
Of their crowns. And in this respect they
differ as widely as in the food upon which
thew subsist. Those of the carn!yoroas, or
those which feed principally upon fesh, have
their crowns sharp and pointed, while those
which live on vegetable food and are peace
able in their dispositions, have fat. smooth
crowns. The human teeth come between
tie two, since they have cutting teeth and
also grinding, whereby they press on the
food for HE proper reception into the stom-
ach. Man therefore has been called an ON.
nifsrou5 animal.
Among the first class Of animals we have
tie Qladrumana. These are divided into
monkeys, simien and lemeBs. According To
Mr. Oven, the difference between these anil
man consists 10 the absence Of the interval
between tie upper lateral inscisor and tie
canine IN man and the comparative small
siLe of tie latter iooth.
A sf5 AZ EaNNg le4 mr.
bat tribe. and these are divided into t.o
Glasses, namely, those that live on insects
and th1se that live on fruits Tie number
II teeth belonging q tie fret are thirty.
eight, 70 the second thirty.
Class third are Cacnivora, or animals that
live On flesh. These are the dog, The hyena,
the weasel, The otter, the badger, Tie raccoon
and tie bear.
Fourth class are the Marsupialia. They
are - called fvr having pouch for The 81.
Communication Of their Young. These are
chiefly the opn.s1m and the Kangaroo.
Nett are tie Rodentia. This order 10.
tludes lie sllirfel, tie rat, Tie beaver. e.
lie inseissofs lurn tie principal eharae-
terisiics u tbi- order.
Tie Edgntsla neat come IN order. These
are tie ant eater. Tie armaJillO AMI The sl1tl.
o. ha. been asgsttained that tie glntic an.
iinai. Is tie hame ol Megatheroils, some q
whose teeth we're foot d length, we're u
ilis elsss.
Tie next. or seventh class. are lie Plrhy.
duaata. tbs tias. inftlles lie elephant,
mas;5dun, fhinUgerUs. h,ppDpatamu.. hog.
bOf,g. Is. Tie mppOp0.4nls Is ! scEy 10
terestiag animal 70 the Dentist. as their
teeth were much used FOR making artificial
teeth before he discovery u porcelain. But
] must hasten on.
Clas. eight are the RgminaBtia. This
order il said II be tie best determined III
al classes u animals. These are the camel,
the lama. dromedary, Ok, sheep, goats, stag.
&c.
The ninth are the Cetaeea. These are
the whales, which have no teeth, properly
speaking. bBthorny substances called whale.
bone Or baluuD