It is camel's hump.

It is not because water enters in this.

Contents of the hump are fats.

Though weight seems also to have the example of reaching to 80kg ,It is usually about 50kg.

The camel can keep not drinking for one week or more in summer, not eating.

Necessary energy by consuming the fat of the hump, the reason is to be able to obtain it.

Therefore, though nourishment becomes insufficient, the hump becomes small,

if nourishment is taken, [it] does to a splendid knar as before at once.

The hump seems to become small and drip to an aged camel.

The knar not only saves nourishment but also :. The sunlight of the intense heat of the desert is prevented.

The temperature from the lower side of the body is made easy to emanate.

Because the camel hardly sweats so as not to consume moisture,

The function of the temperature adjustment cannot make it lack.