The daily national Whig. [volume] (Washington, D.C.) 1847-1849, 1847-11-01

same being. This regarded ms rather inadnlssl-
BILE, until lately German naturalist named krohn,
in the course of investigations the coast oil Sici-
y, nscertaincd distinctly that 1t was the fact and
that In one and the same species there's SET oil iso
lated individuals having eggs which never separate
and form individual groups of animals, while each
individual of these lunches lays isolated eggs which
form free unconncctcd individuals. So then we have
successive generations which do not resemble each
other, and in which the grand parents similar to
the grandchildren but the intermediate generation
never like that which preccdes or follows III We
have in mankind something TO remind MS of this Gu
rious phenomena. we find family ikencsses, US they
called, go through two generations emitting the
intermediate. Certainly that is a corresponding fact
TO this.
These phenomena II is Somewhat difficult to trace,
II is necessary to follow for long while the same
individual, but they have been ascertained beyond
doubt and especially through the care of the Swe-
dish naturalist, Sars 1t is singular, may here re-
mark, that a gentleman should be found in n coun-
try so poor in interesting natural phenomena ready
10 devote himself to the minute investigation of these
phenomena, and succeed in eminent u degree. In
some other portions of Europe on the contrary,
where the facilities of prosecuting such investiga
tons very remarkable comparatively little i'd
vance has been made in natural science.
The next class of which shall speak is the Ecii-
noiern,ala.
The internal structure of this class is more COM
plicated than that Of tho preceding, though il follows
the same plan. We have here also the organs ar
ranged rays round the central cavity. This CEN
trail cavity contains numerous independent organs.
While we had in polyps and medlsn the function of
digestion and respiration produced by one and the
same cavity branching within the recess Of the body,
in this class we have almentary cavity forming
stomach and extending sometimes in several circum-
vontions through the body; and the respiratory func-
ton performed by independent appendages The
fluid is set in motion by organs Independent always
OF the alimentary canal as well as respiratory orr
gans, though all in connection, and in connection
similar to what obtains among the medusa.
Many of the facts which shall add now were not
fully ascertaincd until lately. But recently had an
opportunity of studying the internal structure Of this
class while on board vessel employed in the coast
survey. i have thus been enabled to observe more
attentivey the fishes and discover how intimate
ly allied they are to the medusn and polyps. may
here be permitted to remark that, notwithstanding
the rough material which is at hand the shores Of
the Atlantic for the study of the whole of the types of
radiated animals, there is no work existing the
polyp of the American coast; there is no work in
which you can find even dry catalogue Of this spe-
cies. Though SO many beautiful works on the Nat
ural History of this country and especially of this
State, have been produced, It is somewhat surprising
that there is record whatever Of the radated ami
mails. There is no work on the meduse. These
three classes of radata afford an ample field of inves
tigation, and one which will fully compensate the
labor bestowed upon it. 1t is due TO the cause of
truth and science that the public teacher should not
only ascertain what is known but also what is be
done and here great deal is to be done, this group
having been much more neglected than others of the
animal kingdom. (Appause.)
The most admirable arrangements seen in the ex-
ternul covering Of the echnodermata. II will scarce
y appear credible that these specimens are form
cd Of the same hard plates, arranged in the same
manner, only of different proportions, so that one
presents sphere-like and the other star-ike ap-
pcarance. Butif in the one case, the plates were
little elastic it would be easy to change the form of
the starsh into that Of the echinos and rice pcrsa
After have shown the structure of of these ami
mails trust that this statement will not be regarded
| us ut all exaggerated,
You see two openings In such an animal-an up
per and lower-not always opposite each other.
shall begin with the simplest class before approach
ing the other. Around this single opening five large
plates are placed to leavea space between them
and five smaller plates occupy the interstices. In
each Of these large plates there is hole. Through
these five holes five tubes open. Through these the
series of very different kinds. Alternately we have
series of plates perforated and series Of plates i'm
perforated. Upon those plates without holes we have
large tuberces, upon which the tentacles or spines
movable These FORM were, ten vertical ribs
| from each of the openings TO the other. Through
the holes of Of the series little entaces prorude
having an opening in the end, and which can be re-
tracted and pushed out to disappear or extend
even beyond the points Of the spines; and by these
lentacles the animal as well as by the mo-
ton Of the spnes. These plates, which are imperfo-
rated intermediate. They all meet at the lower
end, where there is another large opening and this
lower opening is the mouth.
These spines are movable, and 1t is their motion
which enables the animal to walk from place to place
In some, the power Of locomotion resides in the mi
| mute tcntaces in the plates
The food is introduced through the mouth, and is
crushed between very powerful plates You find the
jaw very complicated. The complication is SO grea,
that it would require full hour to explain merely the
the structure Of this part Of the animal There is
scarcely any portion of the organization of the ami
NAL creation more complex than the jaw Of these an
imas 1t is formed of almost innumerabe hard plates
| furnished with hard teeth, moved by very distinct
muscles and put in action by a complicated nervous
system. will mention merely that these jaws are
five In number, and are arranged in such manner
to correspond with these ten series Of plates One
jaw is always before an imperforated plate. These
jaws are so powerful that they crush she'll fishes
and the hardest bodies. The intestinal tube is wide
tube provided with several appendages so as to make
1t more complicated than in any Of the other radiated
| animals
But what is more singular in these animals is the
existence Of heart and actual respiratory organs
These tubes, which can b. protruded through these
small holes, terminate by hole, and inside Of the
shell there is in each Of these tubes considerable We
scle which is filled with water, upon which there Is
number of blood vessels. But here these tubes can
be shut and there is another apparatus for injecting
these vesicles in the tube. should have mentioned
that Of these plates is larger than the others ind
there is then sieve Of little holes by which the wa
ter can enter into the body; and by another tube
which comes down in that way and reaches to the
lower opening, oil these minute vescles can be filed
SO that there is an alternate movement Of the water
from outside and through these tentacles and shell
maintain current upon the organs whchare cover
ed with blood-vcssels Respiration is nothing but an
of mir and liuuid vesaola aro