Batkachians. REPTILES. Frogs. 87 
OEDEE, OF BATEACHIANS (Batrachia). 
In all the Batrachia the skin is soft and smooth, and 
generally more or less moist. It possesses the power of 
secreting fluid, and thus materially assists in effecting 
those changes in the blood which in other animals are 
performed by the lungs or gills. All the Batrachians, 
the history of which we are well acquainted with, 
undergo a series of transformations or metamorphoses 
while advancing from youth to maturity. The young 
enter life under an entirely different form from that 
which they are afterwards to assiime. At first emerg- 
ing from the egg, and for some considerable time after- 
wai'ds, their form and structure are essentially similar 
to those of fishes. They have an elongated body, no 
feet, a laterally compressed tail, and external gills. 
The mouth, which is small, is furnished with horny 
hooks or teeth for the separation of vegetable matter, 
and they have a small tube on the lower lip for attach- 
ing themselves to aquatic plants. In this state they 
are known by the name of tadpoles. At a certain 
period of their growth a gradual change takes place. 
In some the external gills disappear, and become 
covered with a membrane, being placed in a sac under 
the throat. The creature now breathes as a fish. Soon 
the hinder limbs begin to make their appearance, 
showing themselves near the origin of the tall ; the 
anterior limbs are then put forth. The lungs, which 
hitherto have been rudimentary, now begin to be 
developed ; the gills are removed by absorption, and 
the animals respire like perfect reptiles. 
All the Batrachians, in their first state especially, 
swim well, and the greater number can also, at least in 
the adult state, walk upon the earth, and can climb and 
even leap with great facility. The form of their body 
indicates as it wmre beforehand the nature of their 
movements. Thus, for example, all those which pre- 
serve the tail in their adult state walk only slowly; 
they can merely drag- their bodies along the ground, 
and usually live in the water, as the Salamanders. 
Those, on the contrary, which lose this member, as 
the Frogs, w'alk on the ground, climb trees, and leap 
with great agility. Taking these their habits into con- 
sideration, as well as their form when in the adult 
stage of existence, naturalists have in consequence 
divided the whole Order of Batrachians into two sub- 
orders or large groups. The first is the sub-order 
Salientia or Leaping Batrachians, by many authors 
called Anouka, or Tailless Batrachians ; and con- 
tains the Frogs and Toads. The second sub-order 
is that of the Gradientia, or Walking Batrachians, 
called by many authors Urodela, or Tailed Batra- 
chians ; and contains the Salamanders, and Tritons or 
Newts, &c. 
Sub-order I. — BATEACHIA SALTENTIA, or ANOUEA (Tailless Batrachians). 
In the catalogue of the species of the Batrachia 
Salienfia in the British Museum, compiled by Dr. 
Gunther, and which amount to the number of two 
lumdred and eighty, this suborder of Batrachians is 
divided into three groups, according to the presence 
Fig. 23. 
Mouth of Polypedates Schlegelii — to show form and structure of 
tongue of the Opisthoglossa. 
or absence and form of the tongue. The greater num- 
ber have their tongue, which is fleshy and somewhat 
bifurcated at the tip, adhering to the jaw in front, 
whilst it is more or less free behind — forming the 
group called Opisthoglossa. or Front-tied tongues — 
fig. 23. A few have this member free in front, and 
form the group Proteroglossa ; whilst there is a small 
number again which have no tongue at all. These are 
called Aglossa. 
The first group, the Front-tied tongues {Opistho- 
glossa), contains more than seven-eighths of the whole 
number of species, and is divided into sections accord- 
ing to the structure of their toes ; one set having the 
toes sharp at their extremities {Oxydactyla), while 
another has the tips of the toes dilated into small pads 
{Platydactyla). The sharp-toed section is composed 
of the true frogs and toads, Panina and Bvfonina, 
while the flat-toed section contains the tree-frogs, 
Hylina ; — 
Kanina, or Frogs. 
The Frogs are in general of a slight, thin form, with 
the hind legs much longer than those in front. When 
in a state of repose on the ground, they carry their 
head very high, and their hind legs are then doubly 
folded on themselves, forming an angle of 45° with the 
length of the body. The muscular system is well 
developed, and the muscles of the thigh and leg parti- 
cularly so, presenting a great analogy with those of 
man. They possess a gi-eat degree of elasticity, and 
in consequence of this, the leaps which these animals 
take when suddenly roused or alarmed, are very great, 
extending sometimes, it is said, over a space more 
than fifty times the length of its body. Frogs gene- 
rally feed upon the larvae of aquatic insects, worms, 
small mollusca, &c. ; and they are sure to select for 
their prey an animal which is alive and in motion. 
They always reject dead animal matter. To obtain 
