TICKING. A strong linen, cotton or union fabric usually woven in stripes of colour; blue and red with white being the most common. The name is de rived from a word "tick," com mon in various forms to many languages, signifying a case or sheath. Its original use was to enclose feathers, flocks or the like for beddings, but its use has been extended to include the covering for mattresses, and for awnings and tents. In some qualities it is also used as a foundation for em broidery.
White, grey or brownish warp threads are usually flax, while the coloured threads are often cotton. The weft is flax or tow. The warps of many of the cheap er kinds are made entirely of cotton, and jute is used for weft in the cheapest grades. A feather tick should be made of fine flax yarns set closely, and there should also be a large number of weft threads per inch.
(Agrostis hyemalis), a North American grass, called also hair-grass, found widely throughout the continent and in various districts occurring in weed-like abund ance. The name is applied also to the somewhat similar witch grass (Panicum capillare), a common North American weed with hair-like flowering branches. At maturity the fruiting panicle breaks away and is blown about as a tumble-weed (q.v.). TICKS, the name for Acari, of the order Arachnida (q.v.), of the families Ixodidae and Argasidae. They have on the head a median probe, armed with recurved teeth, which projects forwards. Ticks are of relatively large size, female specimens of some species measuring half an inch or more in length when distended after being gorged with blood. The mouth parts con sist of two small retractile mandibles, a pair of short palpi and the toothed probe or hypostome. By means of the hypostome ticks pierce the skin and adhere to the host whose blood they suck. In the Argasidae the palpi are simple; there is no sucker beneath the claws and there is only a slight difference between the sexes. In the Ixodidae the second and third segments of the palpi
form a sheath for the hypostome ; there is a sucker beneath the claws and the males have the dorsal integument continuously chitinized, whereas in the females only its anterior portion bears a chitinous plate.
Both families contain pathogenic species. Ornithodoros moubata, belonging to the Argasidae, is widely distributed in tropical Africa from Uganda in the north to the Transvaal in the south. It is the carrier of the Spirochaete of relapsing fever in man. An allied species, 0. turicata, occurs in Mexico and Texas, where it is a pest to mankind and to poultry. Argas miniatus is the carrier of the Spirochaete causing spirillosis in fowls in Rio de Janeiro and New South Wales. Amongst the Ixodidae several forms are injurious to man and domestic animals. Dermacentor venustus is the carrier of the human disease known as Rocky Mountain Spotted Fever. Dermacentor reticulatus, widely dis tributed in Europe, Asia and America, infects dogs with the Haematozoon causing "biliary fever." The same disease results in South Africa from the bite of Haemaphysalis leachi. Ambly omma hebraeum, the bont tick of the Cape Colonists, infects sheep with the Sporozoon causing "heart-water" sickness, and in Europe sheep are inoculated with the same disease by Rhipice phalus bursa. The "coast fever" in cattle in South Africa is con veyed by Rhipicephalus appendiculatus and R. simus. Margaropus annulatus is the carrier of the germ causing the cattle-disease known as "Texas" or "red-water" fever in America, South Africa and Australia. With one or two exceptions, no species of tick is confined to a particular host, and reptiles are infested as well as mammals.