snowstorms to take refuge in the plains of Northern China, where they may be seen in large packs; but as soon as the weather moderates they return to their native deserts. Their flight is remarkably rapid, and when in large numbers the whirring sound made by their wings is heard a long way, resembling the noise of an approaching storm.[1] They are very awkward runners on the ground, probably owing to the peculiar formation of their feet, the toes almost growing together, and the sole being covered with a horny substance like the hoof of a camel.
After their morning meal, the sand-grouse always resort to some spring, well, or salt-lake to drink. Here they will not alight till they have first described two circles in the air to assure themselves of safety, and after hurriedly satisfying their thirst they fly off again. They will sometimes fly long distances to the water.
The Mongol lark (Melanocorypha Mongolica) is only met with occasionally on the desert tract; its habitat is in the grassy portions of the Gobi, and there in winter it is found by hundreds and thousands. Those we saw were mostly in the Southern Gobi; they are also not uncommon in China, at all events during winter.
The Mongol lark is the best songster of the Central Asian desert. In his music he rivals his European congener. He has also a remarkable
- ↑ Marco Polo's recollection of this characteristic is condensed into the words 'moult volant.'—Y.
