The daily national Whig. [volume] (Washington, D.C.) 1847-1849, 1847-10-19

these animals which would enable rs to know them
perhaps better thun we do by their shells. In fact,
when we attompr TO classify them from the she'll il
is not more reasonable than II we should attempt TO
form correct notion Of the character Of people by
looking at their coats Qaughter)
The sofness of this class OF animals is Of their
main characteristics, and they are oil symetrical-
They have right and left hand side, interior and
posterior extremity, an upper and lower side
From the softness OF their bodies these animals have
been called mollusou.
Here the learned Professor demonstrated the ner-
vous system of this type by several diagrams on the
board which he explained to his audence.l
In the next type we find together the lobster and
the butterfly! Nothing seem more dissimilar than
the worm and lobster, and yet the structure is the
same. The body of each is formed Of rings, each
moving on the anterior and posteriorring. The rings
may vary in hardness as those of the lobster. Some
Holsters even have soft Shells Some animals of this
class have coverings soft as the coverings oil the
butterfly Ii we examine the body Of any insect, the
spider the butterfly the grasshopper we find that
II is divided into such series Of rings each movea-
bic on those anterior and posterior to 1t. Even in
the worm-the leech--we have such rings, only in
them they are very soft. Thus we have already one
character by which we can combine the worm with
the crab or with the spider. Between the spider and
the insect with wings there is scarcely any difference
but that constituted by the existence Of wings. The
wings are appendages OF no great importance when
considered with reference to the general organization
of these animals
But the more striking and important difference be-
tween these two types is again to be in the
vous system and Il is matter Of no little importance
that the greatest difference between animals should
be perceived In the nervous system--in the system
which presdes the most important functions OF
animals, and by which their faculties are exhibited
That again has the most striking character and al
ways the same arrangement Of it, and the same rela-
tons 10 the other organs are manifested whatever
may be the external form of the animal
Now, the nervous system Of the worm, spider and
crab is similar that no difference will be perceived
except by those who have paid some attenonto these
subjects.
Here the learned gentlemen illustrated the nervous
system Of this type by diagrams on the board.
In the worm It will be seen there is one nervous
gangion above the intestine, and all the others below
many active centres Of nervous influence as there
are rings. This affords an explanation of the well.
known fact that many of these animals may be cut
into pieces and yet retain the power of regenerating
The portions removed from the diffusion OF the ner
vous influence through these different parts of the
animal.
These details may appear very anatomical and
have little reference to the knowledge Of animals In
general but hope 1t will be seen that without such
foundation it is impossible TO come to an under
standing Of the animal kingdom without which We
cannot arrive at knowledge Of our own nature. The
material physical condition Of our own existence car
by no means be understood without distinct anG
accurate idea of the structure Of the inferior animals
There is really inherent difficulty in these sub
jects Children might just as easily be instructed in
this department Unnatural science in those subject.
which usually occupy the first years of tuition Zap
plause)
The type of animals to which have just directed
your attention is called, from the popularity pointed
out, the drticulatd
The fourth type contains those animals which
have this bony frame in their interior. Though only
the hard portions are represented in the diagrams
yet all have recognised the ostrich and the crocodile
These animals possess what is caleda 'back-bone'-
la continuous column Of bones from the head to tn
tail. Under this column is large cavity in which
the organs of respiration and the ntestines
taned On the anterior part of the body is the mout
the opening Of the Intestinal tube; and the nose
the beginning of the respiratory organs. Yet this
the spy ssyY II hf S4ay ae hs SdsE II pn
which the brain is containA. We have beside al
along the bony column cavity in which is contain
ed substance called the spiral marrow, forming an
Their nervous centre. We have in fact two cavitie
| Of the body-one above and the other below
! This type Of animals has received the name of tn
certebrdtd.
So we have four great tribes of animals character
lied by peculiar external appearances as well as b!
internal differences, of which the nervous system
presents as distinct characteristics as any other.
Thus the location and arrangement OF the nervous
system in the uertebrdted animals present an essen
tial difference from the other typeA In the radidt
and moHusca and artcuata there is but one canal IL
which the nervous system well as the organs ar,
contained wilhelm the the two set
Of organs, those which preside over the functions
the will and those which preside over the functions
which maintain the body in its natural system, are
distributed in two different canals the more import
ant being in the upper and the other in the lower
In the next Lecture l shall proceed to show tina
notwithstanding this great variety of form in the ami
NAL kingdom notwithstanding the great diferenc,
in external apprenticeship animals all of then
in their types-are constructed one and the sam,
identical plan. (Appause.)
Here Professor Agasslz concluded his Lecture II,
was listened to with the most marked attention, b,
one Of the largest and most intelligent audtories W,
ever saw in the College Hail. Many Of the most dis
tinguished of the city were present, and al
were united in their admiration Of the eminently lu
cid and attractive style and manner of one of tn,
most eminent Naturalists of our time.