The Jasper weekly courier. [volume] (Jasper, Ind.) 1858-1922, 1876-04-28


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These animals, in the course Of their
development, 60 through a very singu-
lar series Of metamorphOses comparable
10 those by which a grub is converted
into a butterfly. AT this eason of the
year every. pond is almost certain 10
contain frog-spawn, masses Of transpar-
ent albuminous matter with numberless
imbedded eggs consisting of yelk, black
on one side and white on the other. A
few hours after the eggs are laid the
process of development begins by the
formation of a shallow groove which
appears quickly on the black, more
slowly on the white hemisphere, and
is just such a groove as would be pro-
duced by drawing "A blunt instrument
along the equator Of a soft globe. The
egg is thus divided into two masses. A
second form appears at right angles To
the first, dividing the whole egg into
four; others appear, in definite order,
cutting it up into smaller and smaller
masses until the whole yelk becomes
granular, or formed Of microscopic
cells. Two ridges then appear on the
surface of the egg, and, uniting in the
middle line, enclose a cavity, the lining
membrane of which is converted into
the brain and spinal cord. The head
gradually becomes differentiated, and
the mouth appears on its under side;
the tail grows out, and the little crea-
ture getting too long for the egg be-
comes coiled upon itself, and, before long,
ruptures the egg membrane and makes
its exit from its mass of jelly. 1t is now
To all intents and purposes a fish it has
no limbs, its mouth is provided with
horny jaws, and it breathes by means
of a pair of plumose gills. 1t further
differs from the adult frog, in being
h%erbivorous, feeding on water plants,
to which il attaches itself by means of
two suckers near the mouth. The tad
pole grows rapidly, and before long a
fold of skin appears on each side, which
gradually closes over the gills, leaving,
however, for a considerable time, a
small opening on the left side. In the
meantime the limbs appear, and the
lungs are developed, the tadpole breath
ing for a time both by lungs and gills;
the latter eventually disappear, the tail
shortens, the limbs lengthen, the horny
jaws are replaced by teeth, and an in
sect-eating, ~tailless frog is formed, the
adult air-breathing form having thus
been attained by a wonderful series of
changes, in which the fish Lepidosiren,
perennibranchiate, and triton are all
represented. One would be inclined TO
infer from these metamorphoses that,
on tracing the amphibia back in time,
the story of their origin should be told,
but as a matter of fact archaeological
history tells a different story altogether.
Abundant remains of frogs and toads
are found in the Miocene deposits,
some of which are of so fine IA
character that even the tadpoles are
preserved; but these tertiary frogs and
toads do not differ in any important
particulars from those of the present
day, and the same is true Of the tritons
and salamanders. Some of the latter
attained a very great size, and one of
them-a near ally of the great Japan
csc salamander IF the present day-has
had a very singular fate. having been
described about the middle of the last
century as a fossil by the German
naturalist Scheuchzer, who named il
Homo diluvii TESTS" the man who
saw the flood. In the wealden and Pur-
beck formations no amphibia have as
Yet been discovered, but from the lower
lias to the carboniferous they turn up
again i'm remarkable numbers and Of
great size, but differing from existing
forms in some important peculiarities,
ans affording no help whatever to Il
inquiries as to the origin of the existing
or the tertiary frogs, toads and sala-
manders. Under the throat these gil
gantic amphibia had a remarkable
shield of three bony plates, az well a a
series of plates along the belly. Their
teeth were large and powerful, and pre-
scented an extremely Complicated struc-
ture, whence the group has received its
name of Ldbyrinhodonta .-Nature.