You will see from the pictures facing page 128 that there are two kinds of camels; one kind has a huge hump on the middle of his back; and the other kind has two humps, with a gap between. The _One-Hump camel_ is called an _Arabian camel_, or a _dromedary_. Once upon a time he lived in the country called Arabia; that is the country from where you get your lovely old stories of Ali Baba and Aladdin. But now the One-Hump camel also lives in other countries near there. These are all very hot countries, with many miles of desert here and there. The _Two-Humps camel_ is called a _Bactrian camel_, as he lives in a country which was once called Bactria. That country also has many deserts, like Arabia; but as it is far to the north of Arabia, it is very cold in winter, and the snow then lies very thick on the ground. So try and remember this: The One-Hump camel lives in a country where there are many miles of desert, and where it is very hot almost the whole year. So the One-Hump camel has to guard himself only from the _hot burning sand_. The Two-Humps camel lives in a country where there are also many miles of desert, but where it is very hot in the summer and very cold in the winter. So the Two-Humps camel has to guard himself from the _hot burning sand in the summer_, and from the _cold and snow in the winter_. The Two-Humps camel has in winter a coat of long, shaggy hair on his back to guard him from the cold; and in summer the shaggy hair comes off his back, just as if he were to cast off his thick coat. But the One-Hump camel has only short hair, as the country is too hot all the time to need a thick coat. [Illustration: Bactrian Camel--with Two Humps] [Illustration: Arabian Camel--with One Hump] Now I must tell you how camels are used. First, they carry goods for trade. In those countries there are hardly any railroads, so the merchants carry their packages on camels. Of course they could not put a package right on a camel's hump, as it would fall off; so they always join two packages together with a band or belt, and sling the band across the camel's back, so that there is a package on each side of the camel. When a One-Hump camel is used, the band or belt has two parts, like a loop; and the loop rests over the hump, so that the band cannot slip backward or forward. When a Two-Humps camel is used, the band of course rests in the gap between the two humps, so that it cannot slip at all; and then the two packages can be made very big. That is why people like the Two-Humps camel better for carrying goods, and like the One-Hump camel better for riding. But in some places the One-Hump camel is used both for riding and for carrying goods.