Memphis daily appeal. [volume] (Memphis, Tenn.) 1847-1886, 1867-02-24

with US that plan Of structure which j
common to the birds, and reptiles, ant
quadrupeds, as well as TO man and tht
fishes proper. IL the time permits shal
close with few remarks upon the fresi
water inhabitants Of the type of the Yer
tebrates, worms and crustgcea; but i
not, shall transfer my remarks upef
those classes to my next lecture. i fee
somewhat embarrassed to speak of fishe:
without saying something of the funda
mental differences which exist among
them; and that j may better bring
before you the differences which
characterize the different groups o
fishes, let me draw the outlines ol
some of them, and point out 10 you the
| permanent differences which distinguish
them. Suppose, take, first, our trout.
! You perceive here that the head and
body run together so that there is hardly
/ a distinct neck. That is a characteristic
] feature of all fishes. IL is only ia the
/ class of reptiles that we begin to perceive
1 the first indication OF the contraction
I between the head and body which indi-
Gates the position of the neck. What is
characteristic Of this type Of fishes is the
position of the fin upon the back, which
Is called the dOrsal. There is II large
fin ut the end of the tail, which
may be cut square, as in the
fresh water trout; which may be
fOrxed as in the sea trout; or which may
have its upper end prolonged greatly as
in some other representatives of the
family. This is the caudal, aud that lin
is the organ with which these fishes inn
part to themselves an Onwar4 mOtiOn.
Striking right and left with tie ta:l, the
body is propelled forward ia consequeuee
of this motion, and this motion Is alded
by the dOrsal. This other flu undo the
tail is called the anal. When the hsh
strikes violently and raises that fin, the
surface with which he strikesethe Water
is enlarged but when he strikes gently,
this fin is bent under the tail, aI4d the sur
face with which he strikes the water is
diminished, and the force with which he
strikes being slight, the motion is COM
paratiyely feeble. That fiu is the ven
lraI. This is the only medal line Of the
body. There is one above, the dOrsal,
and one below, the anal, and the caudal
at the end of the body. The caudal in
this group of fishes is always semicir-
cular; that is, the upper half corresponds
with the lower half. IL the tail IS cut
square, then the two parts are about the
same; and If il is fOrked, then the upper
part is the same dimensions as the lower.
IL il rarely the case that one OF those
parts is slightly longer than the other,
and it may be either the upper or the
lower. For instance in the Hying-fish,
which comes very near this, we
have the lower lobe somewhat
longer than the upper. With this, the
moment the fish emerges from the water,
it gives its last impulse by striking vio-
lently to the right and left several times
in rapid succession. We have, also,
upon each Il le of the body, one on the
right and one on the left, these fins,
which are near the head, which are, in
fact, upon the sides of the chest, and
which are known by the name OF the
pectOrals; and these which are here,
upon the lower side of the abdominal
cavity, are known as abdominal fms.
In all the fishes of this group we have
the abdominal fin, half way between the
pectoral and thea anal fins. Now letus COM
pare with that perch, common yellow
perch, as we have them i'll the fresh
water. Here drawing We have q very
different dorsal; there are two, com
monty large. We have the caudal COM
paratively small and feeble We have
the anal placed In about the same posi-
ton e. in the trout, but it has strong
spine in front of the fin. Then we have
the pectorals placed here; and the ven
trails, instead of occupying a medal
position, are placed just below the
peOtOrals, and the front part OF the ven
trails sustain a strong spine. You see at
once what a difference that makes.
This first fin consists Of strong
Spiues, while the second fin con
sists OF 8 number Of rays which are
divided and subdivided so that the
whole fin is soft and tender, while this Is
very hard and prickiy. Scare the spines
here; so are the spines there; and or the
sides Of the head there are other spines
connected with the bones Of the head.
But that is not all. Let US examine the
mouth. Here the mouth is very widely
cleft perhaps; but there are also perches
in which the mouth is very widely cleft.
But the principal difference is that
here, in the trout, the anterior part
of the upper jaw is made up Of
one bone, and the posteriog part
of the upper jaw of ansoier hot,@,
which two bones are placed one in
succession to the other, forming one
arch, and both have teeth along their
lower edge. These two bones are
exactly the same as those which form
the upper margin Of our own mouth.
4 T.
pied by the cutting teeth then follow
the eye-teeth, then the grinders. Now
there ere two eating teeth, on the right
and left side, which are implanted III a
bone which corresponds TO this, and is
called the intermediary. The eye
teeth and grinders are implanted in an
other bone which is called the upper
maxillary, and the intermediary and
upper maXillary together, in one arch,
form the margin of the WOuth. Now in
the peTch il iS very different We have
one bone which extends in this way
from the anterior part OF the mouth
to the end .lbf the cleft, and that one
bone is provided with teeth along its
and forms alone the upper mar |
gin of the mouth; while another bone, |
placed behind, and forming in no way a
part Of the mouth, sgstgiiNug No teeth /
whatever, represents the upper maXil- |
larry. 1t is the anterior bone which |
the Intermediary so that |
the proper jaw-bone in the perch has not /
a tooth. II loes not form a part Of the }
anterior margin Of the mOutli while the |
intermediary is so large that it alone I
forms the arch of the upper part Of the /
mouth. These are the most prominent |
that We have here. aud now !
there are fishes OF a very diff rent type |
from these draws the outline of fish |
on the blackbOard suppose you may I
recognize here q shark. Applause. 1t
differs from the two types of fishes / |
have described thus far in having five
clefts upon the sides of the head which /
are the gill openings. The troHt has
only one, and SO has the perch only one, /
and that cleft is supported by bony
plate which moves TO and fro upon the
gills and pTGtelts thea during raspira
ton. And so has the perch, while the
shark has no such bone, and the BRAN
chial iissures are open in advance Of the
large fin, which is placed upon the side.
and the ventral has again the same posi-
tinn as in the trout or salmon, while the
tail is remarkable for the prplOnga-
ton Of its upper Lobe; and that Is
rot only an external prOlOngatiOni
but the backbone itself extends into
this lobe to is very end. SO that its
backbone does not terminate as in other
fish, with broad blade supporting the
tail, or as in the trout, salmon and the
like, but the backbone extends to the
very end All these fishes, moreover, /
haze their sOIid frame, that is their skel-
etOn, soft and consisting more Of car
tilage than bone. Then we have another
type, the sturgeon family. Makes Il
drawing of the sturgeon on tile black
board. 1t differs from the shark, IN hay
ing tire gills projected like the other
fishes by a bony plate, so that
the gilis are covered externally.
In having the enQat 20 prOlOnBsdi
the mouth is far below the head. And
then it shares with the shark that singu-
lar prolOngation in the tail which | have
noticed. And it has that very singular
feature, that the ventral fins occupy the /
middle Of the abdaminal region, half
way between the peet0r2ls and the
anals. And finally, there is this last
type of fish makes o drawing of it,
which IL quite CURIOUS for 3 elongated /
form for tile truneatea Termination OF
the head, which is, as il were, cutsquare;
and for the presence Of the simple fin /
extending all over the body, without any |
pectorals or ventrals, but with a number |
of small openings upon the side, as
many as seven. and one upon the |
back tt u called tns lanlper eel. |
To these groups belong all the /
fishes known on the earth and to these |
Rroops may be referred all the fishes that |
have live4 in ali tlIaes. lAppiauset But |
then they assume such extraordinary /
in details that by a process Of !
some part or other, we can at |
once see how one might have grown out |
of Inc Othert or that we Gan see that by /