The flowering tops are harvested when the plants are in full bloom and are dried in the shade to preserve their green color. In case the herb is grown in large quantity, it may be cut with a mowing machine, the cutter bar of which should be set high. The plants should lie in the swath until partially dry, and the curing may then be finished either in small cocks in the field or in the barn, care being taken to preserve the natural green color as far as possible. Returns from experimental areas indicate that a yield of about 2,000 pounds of dried flowering tops per acre may be expected under good conditions. The herb must be carefully sorted and all the large or coarse stems removed, after which it may be made up for the market in bales of 100 to 300 pounds each. Prewar prices to collectors ranged from 2 to 4 cents a pound. The prices in June, 1920, for the herb were 5 cents; for the leaves, 10 cents; and for the leaves and flowers, 14 cents a pound. CHAMOMILE. (See CAMOMILE.) CONIUM. Conium, or poison hemlock (_Conium maculatum_), is a large, poisonous European biennial plant of the parsley family, naturalized in the Northeastern States and in California. The full-grown but unripe seeds (fruits) and the leaves are used medicinally. Conium is easily grown, and has been found to thrive in both comparatively moist clay soil and in dry sandy loam. In rich, moist land it may easily become a troublesome weed. Conium grows readily from seed, which may be sown either in the fall or early in the spring in drills 2 or more feet apart. As soon as the seedlings can be distinguished in the row, cultivation similar to that given ordinary garden crops is begun. The plants usually blossom in the second year, and when the oldest seeds are full grown but still green in color the plants are harvested and the seed at once thrashed out and dried with the least possible exposure to the light. The small and undeveloped seed should be screened out and rejected and the good seed stored in containers that will exclude light and air. The leaves are collected when the plant is in flower, quickly dried in the sun, and stored in the same manner as the seed. Estimated yields at the rate of 600 to 800 pounds of seed per acre have been obtained, but the yield is very uncertain, since the flowering plants are especially subject to the attacks of insects which destroy the crop of seed. The prewar prices as quoted in the wholesale drug markets ranged from 5 to 10 cents a pound for the seed and 5 to 6 cents for the leaves. The prices in June, 1920, for the seed were 35 to 36 cents, and for the leaves 25 to 26 cents a pound. CORIANDER.