The Wheeling daily intelligencer. [volume] (Wheeling, W. Va.) 1865-1903, 1874-05-23
GkeG8tquifqenre
EVOLUTION AND ANATOMICAL.
y s-.s FORMS. +!
Tho Facts OF EmbryologY and OF
Anatomy Lend Powerful support
In tho Theory Of Mr.. DnPyyIn

Tho Facts OF Embryology and oil
Anatomy Lend Powerful support
TO tho Theory OF MIR. Darwin.
(Tenth article, showing how, while fostal do
Vel0pment and organic structure give strong
Arguments in favor OF Dafwiniam, they can b
explained In no other Way
RditOts Of the Intclllgenecr. .....
Ono Of the most lorciblo arguments
which can be adduccd in favor OF the
theory OF organic evolution is furnished
by tho facts Of embryOlOgy. AS was long
ago pointed out by Won Baer, the "venef.
able Nestor" Of that science, all organisms
whatever arc alike at the earliest stage Of
their existence. Mere specks Of proto-
plssm at first, the differentiation which
distinguishes plants from animals soon
begins. at the outset all animal germs
seem alike. AS development proceeds,
each gradually assumes the characteristics
Of the sub kingdom TO which it belongs,
but even alter this progress has been
made, the embryo members Of any given
class are indstinguishablo from the
embryo members OF any other given class
within the same sub.kingdom. The germ
Of man cannot be distinguished from the
germ OF dog. Of reptile, Of a bird, or Of
fish, hut alF resemble the adult form oil
an dnlosba, which, in classification, Is the
starting point Of the Ctrte6FGtd. As de-
velopment goes on, each assumes the
characteristics successfully Of Its class,
order, family, genus, species and variety.
Says Won BaCr: "In my possession arc
two little embryos in spirit, whose names
have omitted to attach, and at present l
am quite unable to say TO what class they
belong. They may be lizards or small
birds, or very young mammalis, so COM
plete Is the similarity in the mode oil for
nation OF the head and trunk In these
animals. The extremities, however, arc
still absent in these embryos. But even
iithey had existed In tho earliest stage OF
their development, we should learn no.
thing, for the feet Of lizards and NAM
mails, the wings and feet Of birds, no less
than the hands and feet Of man, all arise
from the same fundamental FORM"
NAN IN MS EMBRYONIC DEVELOPMENT.
Let now select the human embryo as
finally becoming more highly developed
than the embryo Of any other vertebrate.
Gradually progressing, It develops beyond
the appearance Of an embryo fish, but still
resembles the embryo reptile, the embryo
bird, and other embryo mammals. Be-
coming in turn more unlike the rcptiliRn
germ, and then more unlike the embryo
bird, 1t shortly afterwards diiEerentiates
from tho lower mammalis ofsimilar age.
"Fotif weeks alter conception, tho en-
bryosot the man and the dog can scarcely
DO distinguished from each other, but
have become perceptibly different from
the corresponding embryos Of the chicken
and tortoise. At eight weeks few points
oil difference between the dog and the
man become perceptiblc; tho tail is short.
erin thehuman embryo, and the Cerebrum
and Cerehellum have become larger, re-
latively to the corpora quadrigemina, than
In the embryo Of tho dog; but these differ.
enceB.are less striking than those which
separate the two mammals on tho one
hand from the reptile and bird on the
other At d later stage the human embryo
becomes still moro unlike that Of tho dog,
acquiring charaCterisLics peculiar to the
order Of primates to which man belongs.
LASTLY, the foetus Of civilized man, at
seven months, is entirely human in Gp-
pearance, but still has not thoroughly &C.
quircd the physical attributes which dis.
iiuguish the Caucasian from the Austria
lian or the negro" In carly foCtal exiS-
tence, tho human embryo develops as
though it were going 10 become fish. It's
rudimcnt OF q heart resembles that Of 8
fish, and Its blood is circulated through q
vascular system with arteries branching
through gill.lIke Sits, which in tho case
of the embryo fish develop into It's breath.
Ing apparatus. In man and in the higher
mammals this vascular system Is soon re.
placed by a membrane called the allantois
which Is like the system which in reptiles
and birds Is developed from their former
gills, This Same membrane dwindlef
away and becomes aborted In the impla-
GENITAL mammals such as tho kangaroo
opossum, &c, while in the higher mann
mails 1t Is converted into the placenta and
becomes the channel oil intercommunica-
tIOn between the mother and offspring. In
the human embryo, rat later period there
Is movable tail considerably longer
than tho legs; the great toe projects side
ways from the loot like the toes Of adult
qnSdrumana; and during the sixth month
the whole body is covered very thickly
with hair, extending even over the fact
and ears-Gverywhere, indeed, save or
the lower sides Of the hands and feet
which are also bare In other mammals.'
In many animals We may observI
changes during even the half grown con.
dilon and the adult state. The whelp
Of the lion and Of the puma arc frequent
lystriped like their feline ancestor, thougl
when grown they arc always tawny
The young OF blaCkblrds arc usuall
spotted, like other birds oil the thrus
tribe, who probably came from o commo
progenlior.
ABORrED LIMBS AND usELEss ORGANS.
Again, In many animals VIC find pei
iecly useless and atrophied organ
which, In tue embryo stage were Cntirel
developed. Thus, tho loetal whale ha
teeth which arc never used, and teet
are also found In tho beaks of certain en-
bryonic birds. The boa. constructor 20
sesses o rudimentary pelvis, and hin
limbs which never como through Il
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