Savannah courier. (Savannah, Tenn.) 1885-1979, 1889-07-18
THE BATRACHIA.
Points About the Clammy Musl-
clans of the Marshes.
Thcy Have Played an Important Part In
the Development of Physiological
Science Their Many PocuIiari-
ties Various Species.

1t is true that the frog is common
and rather despised animal. At q
casual acquaintance there is nothing
attractive about him, either in appear
ance or behavior.
But while the frog at first acquaint-
ance seems in nowise a noteworthy
animal, it is still true that no living
creature of the fields and streams is
in as many ways so interesting. 1t is
a classic animal in the field of expert
mental physiology. 1t was in the web
of the frogs foot that that fact of
fundamental interest in the medical
treatment of disease-the circulation
OF the blood-wa first definitely OBJ
served. And it was the accidental OBJ
servation of Calvin, made in 1890,
that q pair of frogs legs, suspended
on a copper hook and in contact with
a plate of iron below, were
thrown into violent contractions, that
led to the discovery of Galvanic (now
chemicaD electricity. Endless exper-
iments have been made upon the It's
sues and organs of the frog, all throw
ing light upon the physiological action
OF the corresponding parts in the hui
man body. For example, the muscles
of a frogs leg may be so dissected as
to expose the nerve connected with
them; if the nerve be then stimulated
by current of electricity or even by
pinching, the muscles will contract.
In this way much has been learned
about the physiology Of these tissues.
The reason why the frog is especially
available for the purposes of physio-
logical experiments is that its tissues
are exceedingly tenacious of life.
Under suitable conditions the muscle
and nerve preparations just referred
to will respond to stimulation several
hours after the life of the animal has
been taken. The remarkable power
of retaining vitality is still better seen
in the action of the heart, since this
organ will go on beating for two days
after life has ceased in the animal.
This same tenacity of life is true Of
some other reptilian and other low
animals, as birds and mammals.
The frog, then, having so well estab'
lished claim ON our interest, is de.
serving Of some notice in respect tc
its specific characters as an animal.
The place which it occupies in the
scale of animal life is intermediate be-
tween that of the fishes and the rep
tiles This is indicated very clearly In
the history of its individual devel
opment. 1t is we'll known that In
what may be called the period o.
youth in the frog the form Of the body
and the manner of life are quite differ
ent from the same in the full-growr
animal. Now in the early part of this
tadpole period the creature has all o
the essential characteristics OF fish
lis body is elongated and terminates il
broad fiat tail. There are no legs ant
it brcathes by means of gills. At thi'
time, too, it lives on plant food, crop
ping the leaves of water plants b.
means of horny plates with which
its Jaws are provided. But whel
the tadpole stage is passed ant
the frog nature fully acquired
the animal then possesses all tn
distinctive characteristics of reptile
1t has two pairs of limbs, a scaleles
skin. and breathes by means of lungs
of these changes the most striking /
that from a water-breather (air dis
solved in water) to an air-breather
II Is for this reason that the frog, to
rsther with other animals possessing
the same popularity, is placed in tn
Geological class. Amphibia, the wor'
,raaning double-life. Some natural
Its. however. prefer the name Bs
,raehia. the original meaning Of thi
word being frog.
The length of time required for tn
Development Of the frog anpears :