The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1839-04-26 00:00:00

On Saturday evening T. Rymer Jones, Esq. delivered the
second of his interesting lectures to a numerous audience.
We were glad to find a decided improvement in the attend-
ance, and we feel certain that when the peculiar merit of
these lectures becomes generally known, they will be as popu-
lar as any delivered at the Institution.
We have in this lecture to consider the locomotive organs
of those animals, which are more perfect in their general
structure than those which came under our notice on the pre-
vious evening, and in doing so, shall have to trace the de-
velopment of legs and arms, which we shall find to be the
agents employed for this purpose. Previous to doing this, it
may be well to notice that there are animals capable of loco-
motion, which do not possess either of these organs, and yet
are well adapted for the purposes of their existence. Thus
we find that serpents are able to move with ease from place
to place, and when we observe their movements and habits,
it is impossible to withhold our surprise at the manner in
which the deficiency of the usual locomotive organs is com-
pensated for. The serpent class of animals are not only able
to make progress upon the land, but leaving the land can
enter upon an aquatic existence, and swim when circum-
stances require. They can climb with ease the highest trees,
and gaining the topmost branches, assail the birds which
resort to such positions for protection. They are not con-
fined to this kind of motion, for if they choose, by coiling up
their bodies they can by an elastic spring, dart to a consider-
able distance upon their prey, and secure it however agile
it may be. By their simple flexibility they are able to ac-
complish all these wonderful movements. But leaving the
serpents which are entirely devoid of legs, let us examine the
gradual development of these organs, and notice how, step
by step, as the animals become more and more perfect, these
appendages likewise attain a greater degree of perfection.
There are some serpents, which if we strip off their skin,
we find to be provided with rudimental joints, which are the
first sproutings of legs. Proceeding a little further up, these
rudiments become larger and larger, but still useless as organs
of progression. In this manner we go on, until in the lizard
we first witness the serpentine class of animals with these
organs, for the purposes of locomotion, and in this tribe we
find them elongated and transformed into four short legs.
We see from this, that even the limbs we possess may be traced
from their first beginning, until they actually arrive at their
highest state of perfection.
Fishes, we are aware, are so contrived as to be able to live
in water, and pursue their way through that fluid with rapi-
dity. For this purpose they are constructed upon beautiful
mechanical principles, so as to enable them to oppose the
least possible resistance to the medium through which they
urge their way. Where are the oars by which the fishes ac-
complish their motion ? We are Usually told that the fins of
fishes are the oars by which they swim, and as in human me-
chanics the tail is the rudder which directs their motion.
Nothing can be more at variance with the truth, as it is by
the flexibility of their large and powerful tail that they scull
themselves'along, and it is by the fins that they direct their
course. These fins have from twenty to thirty joints in them.
There is another mechanical contrivance which we meet with
in the fishes with which we are familiar, namely, those which
inhabit the upper regions of the ocean. This is an hydro-
static apparatus which enables them to come to the top for
respiration, and to sink to the bottom without the necessity
of using violent muscular efforts. This apparatus consists of
an air bladder, which they expand or contract as occasion re-
quires. There are, however, fishes, which being destined to
live at the bottom of the ocean, are not furnished with this
contrivance, such as the skate ; but upon examining these
fishes, we find their system of fins much more extensive and
powerful, so as to compensate for this apparent inconveni-
ence. The eyes of this class of fishes are situate upon the
belly, so as to enable them to look upward. There an: fishes
which are enabled to leave the water occasionally and to come
upon land. The eels are in this predicament, and they leave
the water in which,they may be, and wander over the mea-
dows in search of waters more suitable to their existence.
The climbing perches can climb the trees in the neighbour-
hood of the water in which they exist, in search of the insects
which are to be obtained in such positions. Their fins are
thus applicable to other purposes than swimming. The
flying fish have their fins converted into means of flight, and
by their means these persecuted inhabitants of the deep are
enabled to leave the element in which they live, and to dart
for a brief space of time into the elements above.
In turning our attention to the quadrupeds, we shall begin
with those which inhabit the ocean. W e must expect that
quadrupeds of this kind will more or less resemble fishes. The
whales are the representatives of the quadrupeds which are
met with in the ocean. These creatures of enormous bulk
live upon the surface of the solitary deep, and there breathe
the same air as other quadrupeds do which inhabit the land.
They are not animals which breathe by gills as other fishes
do, but by lungs as we do. The blood of the whales is hot,
as ours is •, and this heat must be incessantly continued by
some mechanical contrivance. We find that if animals are
exposed on the surface of the earth to wintry cold, they are
well wrapt up in a hairy or a woolly covering, to prevent the
radiation of their heat. But how are we to prevent the escape
of the heat of a whale ? The provision of nature for this
purpose is simply to remove the hair from the surface of the
body, and to replace it by a strong and thick blanket of fat,
which, being placed beneath the skin, answers the same
purpose as the hair upon other animals, and does not at all
interfere with its movements. But where are the legs of
these whales, which we have called quadrupeds ? If you
examine these creatures attentively, you will observe that
they are furnished with only two fins, but that the tail is
remarkably spread out, and, unlike that of other animals, is
placed horizontally instead of vertically. Now trace these
circumstances in connection with the habits of the whale.
As it must breathe, it must come to the top of the water.
Its nostrils are placed at the back of the head. It is suffi-
cient for the whale to protrude the back of his head from the
water to enable him to breathe. The existence of one pair
of fins near the head is evidently sufficient to elevate the
head so as to render breathing possible. But there are some
of these creatures which are not strictly confined to the water,
but which can come ashore. The seal and walrus are ani-
mals of this description. Now, if we contrast the structure
of the seal with that of the whale, we shall find that there
are the same paddles existing, but much more perfectly
formed ; that there are fingers projecting through the extre-
mity of the membrane which covers them ; that these are
armed with strong nails, and capable of performing exten-
sive movements; that the hind legs now begin to appear
furnished with strong membranes, so as to convert them into
strong oars. Thus furnished, the seal not only swims with
great rapidity along the shores, but, whenever circumstances
require it, scrambles out upon the banks, and enjoys itself
upon the shores of the ocean. There is one unfortunate seal
which must find it painful to drag itself upwards, on account
of the imperfect condition of its tins. We find that its canine
teeth are made to grow downwards to the distance of a foot
and a half from the bottom of the upper jaw, and, by means
of these strong teeth, the walrus makes up for the deficiency
of its posterior fins, for, by using them as hooks, it can drag
itself upon the rocks whenever occasion renders it necessary.
Let us now proceed to consider the structure of the feet
of quadrupeds which live upon the surface of the earth.
How various is the form of these organs !—to what a variety
of purposes are they adapted ! And yet, if we examine them
in detail, one after the other, the differences are so slight
that the anatomist has much difficulty in tracing them.
Notwithstanding this, I must, upon the present occasion,
select a few striking examples ; and, by contrasting them
with one another, shew the admirable adaptation which is
displayed in this part of the animal kingdom. We will begin
with the foot of the horse, as one of the most imperfect with
which we are acquainted ; and yet, is there any part of it
which can be pointed out that is not a miracle of mechanism ?
The very circumstance of its hoof not being divided, renders
the horse better adapted as an assistant to human labour.
It is evident that, if the hoof were divided into fingers, the
animal would not be enabled to use such violent efforts in
the way of drawing as we find the horse to do. The softer
portions of the foot are so beautifully locked into the harder
ones of the hoof, that no portion of the former is found to
suffer from the great strain which the horse places upon
it. But the foot of the horse may be changed into a
variety of others, ill adapted for drawing, but well adapted
for the animal possessing them. The huge elephant, as it
moves its enormous bulk over the ground, has necessity not
for legs, but for pillars ; and it will only be necessary to look
at the foot of the elephant to find that it is well adapted for
the great weight which it has to sustain. But these pillars
may become stilts. The giraffe inhabits the hot and sand
plains, and finds no other nourishment and support except
from those few trees which are found upon the banks of
rivers ; the mimosa tree for instance, which bears its leaves
at a very considerable distance above the ground. But how
is the giraffe to arrive at the leaves of the mimosa, how is it
to stretch itself to such an height, or to climb so high ? It
would be impossible by any other contrivance, and therefore,
the instruments which in other animals are adapted to such
various purposes—in the giraffe are converted into stilts.
We find in the kangaroo, and the jerboa that the hind feet
are intended for leaping to considerable distances. For this
purpose they are very long, and that the fore legs are left of
diminutive proportions. To enable the squirrel race of ani-
mals to leap from tree to tree, without increasing the strength
of their legs, between the fore and hind legs there is a strong
membraneous portion of the skin, capable of being stretched
out ; when, therefore, the flying squirrel makes a leap, it
spreads out its feet, and forms a parachute sufficiently large
to keep it above the ground, and enables it to spring to much
greater distances than without such assistance, it would be
capable of doing. There are quadrupeds which live beneath
the ground. How are we to convert any of the organs which
we have as yet seen to such a purpose as this, and yet to
retain the essential form of the organ. The fore feet are
shortened to the utmost degree, are extended in breadth, are
gifted with hands and nails, and turned upon one side, so as
to enable the animal to scratch away anything which may
obstruct its progress. This is the contrivance which enables
the mole to move itself beneath the ground, and to hide
itself there. All that we generally know of the mole is, that
it is capable of injuring the farmer's labours by throwing
up mole-hills, and it is therefore killed without mercy, when-
ever the farmer has an opportunity of getting at it. How
far this may be theory, I leave practical men to say, but that
the mole is an useful agent in draining lands by the holes
which he makes beneath them, is certain. You will find that
the mole's habitation is fitted out with the greatest ingenuity.
As the mole' has many enemies, every form of escape has
been attended to. In one of the highest mole-hills thrown
up by the mole, you will find its principal' abode. In fact,
its cells are thus constructed. A circular chamber or gallery,
is cut out in the upper part of the mole-hill, and a second
circular chamber of similar dimensions is made in the base
of the hill, and these circular galleries communicate with
each other by five distinct passages. Now this is a con-
trivance for escape, which every one must admit. If it is
disturbed in the upper gallery, the animal descends to the
lower one, and the injury must be great indeed to destroy
the whole structure at once. For communicating with the
lower gallery there is an excavation still deeper in the ground,
and from this excavation another gallery is made, plunging
deeper still, and rising up to join a road leading from its
quarters to distinct parts of its domains. Thus, whenever
the mole is attacked it has abundant means of escape and
preservation. From the central division there is invariably a
road which is called the main road. A French naturalist
anxious to ascertain what the mole was doing under ground,
inserted straws at different distances along this main road
and surmounted them with little flags. He then alarmed the
mole, and the falling of the flags indicated the period of the
passage of the mole. He then found that the average pace
at which the mole travelled was not less than that of the
horse going at a brisk trot. We find that quadrupeds are
enabled to fly in the air by having their arms drawn out to a
great extent, and being provided with a membraneous covering
over the fingers. Here is a wing made out of an organ which
in the last instance was used as a spade,—and by the simplest
possible contrivance. This conversion of a leg into a wing
renders several other mechanical contrivances necessary.
How is the bat to make its way when it alights ? The bat
does not generally alight, but clings to old walls or trees.
The fingers are drawn out and covered with skin, but the
thumb is still left free, and forms a hook, which, whilst
the fingers can he used as wings, can be used as a hook
for grasping. If you watch a bat asleep, the feet are
turned to some account, for by means of them the bat hangs
with its head downwards, by which means it is protected from
danger during sleep. The bat flies with the greatest rapidity
and nearly in the dark when in the open air, but in the dun-
geons in which it lives, absolute darkness may be said to con-
stitute its usual abode. Now, if a bat is to fly with fearless
rapidity in the dusk, how is it to make its way against the
obstacles which may be opposed to it. It has been found
that when bats are artificially blinded, or their eyes put out
in order to prevent them from seeing at all, and obstructions
of all kinds placed before them—even strings made to cross
each other, in all directions in the apartment where they are
brought—none of those obstacles could prevent the bats from
threading their way through them without touching them.
What contrivance was there to enable the bat to steer its way