From Roy Chapman Andrews' excellent book 'Across Mongolian Plains' published in 1921.
Running to the spot where the head had been I found a beautiful brown-gray animal lying behind a bush. It was no larger than a half-grown fawn, but on either side of its mouth two dagger like tusks projected, slender, sharp and ivory white. It was a musk deer – the first living, wild one I had ever seen. Even before I touched the body I inhaled a heavy, not unpleasant, odor of musk and discovered the gland upon the abdomen. It was three inches long and two inches wide, but all the hair on the rump and belly was strongly impregnated with the odor.
These little deer are eagerly sought by the natives throughout the Orient, as musk is valuable for perfume. In Urga the Mongols could sell a "pod" for five dollars (silver) and in other parts of China it is worth considerably more. When we were in Yun-nan we frequently heard of a musk buyer whom the Paris perfumer, Pinaud, maintained in the remote mountain village of Atunzi, on the Tibetan frontier.
Because of their commercial value the little animals are relentlessly persecuted in every country which they inhabit and in some places they have been completely exterminated. Those in Mongolia are particularly difficult to kill, since they live only on the mountain summits in the thickest forests. Indeed, were it not for their insatiable curiosity it would be almost impossible ever to shoot them. They might be snared, of course, but I never saw any traps or devices for catching animals which the Mongols used; they seem to depend entirely upon their guns. This is quite unlike the Chinese, Koreans, Manchus, Malays, and other Orientals with whom I have hunted, for they all have developed ingenious snares, pitfalls and traps.
The musk sac is present only in the male deer and is, of course, for the purpose of attracting the does. Unfortunately, it is not possible to distinguish the sexes except upon close examination, for both are hornless, and as a result the natives sometimes kill females which they would prefer to leave unmolested.
The musk deer use their tusks for fighting and also to dig up the food upon which they live. I frequently found new pine cones which they had torn apart to get at the soft centers. During the winter they develop an exceedingly long, thick coat of hair which, however, is so brittle that it breaks almost like dry pine needles; consequently, the skins have but little commercial value.