Write the external features of the Frog.

EXTERNAL FEATURES OF THE FROG:

A frog has greenish spots and dark lines on its skin which is kept moist and slimy due to the secretion of glands. Its ventral side is yellowish white in colour. The body of frog consists of head, trunk and limbs Neck and tail are absent Head directly joins with the trunk and therefore it can not move its head. The conical head has two large bulging eyes. .Behind each eye is a circular area called tympanic membrane. These membranes help in hearing At the tip of the snout, it has two openings called external nostrils through which the frog breathes. There is a membranous skin between its toes, which help in swimming. There are five toes in each foot but the hand has only four fingers because the thumb is rudimentary. In male frog, the first finger is thicker than the others. The eyes of frogs have two eyelids. An upper eyelid which is immovable and a lower eyelid which is slightly movable. A transparent membrane, the nictitating membrane is attached under the lower eyelid. This membrane can be drawn upwards over the surface of the eye to clean and moisten it when the frog is on land and to protect it when the frog is in water Frogs lay eggs in winter season in water. They hibernate (go to winter sleep) by burying themselves in the mud for the whole winter.