HORNING. 217 HORNTAIL. HORNING, Letters of. In Scotch law, a writ which issues to compel a party to execute or carry out a judgment or decree of the court. The writ was formerly the only form of enforcinj,' civil decrees by imprisonment, except in the case of small debt decrees. The process has been shortened, and other forms of execution are now more commonly employed. The title of the writ is derived from the ancient custom of denouncing a person disobeying the writ with three l)lasts of a horn. This was technically called 'putting him to the horn.' HORNITOS, hOrne'toz, or HORNOS (Sp., little ovens). The name given to the low oven- shaped hillocks which emit smoke and vapors, and which occur in great numbers on the sides and in the neighborhood of the large volcanoes of South America. HORNPIPE. See Black Gum. HORNPIPE. A lively English dance, origi- nally in I, later in | time. The universal pecu- liarity of the music was the length of the final rote in each phrase. Its history can be traced back to the sixteenth centurj' in England, and to about 1740 in Scotland. During the eighteenth century it was widely popular, but since then it has been distinctively a sailor's dance. HORNS. Under this term are commonly con- fused two very distinct structures forming out- growths on the head of ungulate animals, to which order they are confined. The word ought not, strictly, to include the bony antlers of deer or the girafle, since these, although to a certain extent epidermal outgrowths, consist of true bone built up from blood deposits, and are not at all transformed cuticle or 'horn.' Neverthe- less, as Beddard points out (in Mammnlia, Lon- don, 1002), the difTerence is one of degree rather than of kind. The simplest condition is seen in the giraffe, each of whose paired horns is a slraiglit, bony outgrowth, the os cornu, originally separate from the skull, but becoming permanent- ly fused with it early in life, and is covered with wholly unmodified furry skin. In deer there is the same os cornu. which may here be branched, and never becomes fused with the skull, but, on the contrary, is shed and renewed annually, and is covered with a skin modified into 'velvet' (see Deer) which decays and drops off as soon as the hom-core (antler) is perfected. Between these two falls possil)ly the extinct Sivatherium (q.v.). and certainly the modern pronghorn (q.v.). Here the bony core (os cornu) is fixed as in the giraflTe, but begins to be branched as in the deer; and it is covered by a sheath formed of agglu- tinated hairs, the hairy skin beginning from the tip of the horn and jiroceeding downward, gradu- ally transforming into perfect horn, which is shed and renewed annually. This is an isolated case, but connects the giraffe and deer with the Bovida-. or proper 'hollow-horned' ruminants (Cavi- cornia ) . In this family the males of every spe- cies, and in most cases the females also, j)ossess upon the top of the skull protuberances of bone into which air-cells often extend front the frontal sinuses. These are cal' d 'horn-cores.' and form the support of the cornubus sheaths that cover and often extend far beyond them. They are not present at birth, for obvious reasons, but begin to grow inuuediately aftenvards. The horn- sheaths grow with them, and continue even after they have reached normal size to push out at the base as fast as they wear away at the tip. Their form and position on the head is characteristic of each group: round and lateral in the oxen; slender, retrocurved or twisted, and somewhat compressed or sluirply keeled in most antelopes; heavy, cross-ridged, triangular in section, and often spiral in the sheep and goats, and so on. Evolutionists regard horns as, in most cases, a secondarj' sexual character. An examination of the fossil history of the tribe shows that these appendages have been gradually acquired, and it is only recently that the females of many forms, now provided with small horns, have acquired them by heredity. Moreover, castration or injury to the reproductive organs is likely to affect the growth and size of the horns. Lastly, among the deer, where the does (except in the reindeer) are hornless, these appendages are acquired just pre- vious to the mating season and are dropped when the breeding season is over. Their service as weapons of defense and offense is, therefore, large- ly, if not primarily, in contests with each other for the supremacy of the herd — that is, in the combative process of sexual selection. Tiiey are, nevertheless, in many instances, powerful weap- ons in resisting and attacking outside enemies. The spear-like thrusts of the lowered horns of an enraged sable, or other large, long-horned ante- lope, are feared even by lions and leopards, which more than once have been killed by them. The goring power of a bull is irresistible. A heavy sheep, armed with its great horn-coils, is a 'bat- tering-ram,' indeed, not to be despised, ilany, however, seem to be ornaments rather than weapons of value; or tools helpful in various ways, as snow-shovels, for one pertinent example, among the reindeer. Some of the great extinct ungulates of Tertiary time had very powerful horns, especially Coryphodon and the group of great Dinocerata, where in some cases a pair upon the forehead was supplemented by one or a [lair on the snout. At present, a ruling dis- tinction between the artiodaetyls and perisso- d.ictyls is. that in the former the horns are al- ways paired ( in one modern case. Tetraceros, two jiairs) and on the forehead; while in the latter they are set on the nose, and are single or two in number, one behind the other. This is the case with the rhinoceroses (of which one vi'ry early form only had a paired arrangement), where the horn is a growth from the skin of the nose, composed of a solid mass of agglutinated hairs, based upon a knob of the underlying nasal bones. HORN'SEY. .V suburban municipality of London, England, six miles north of Saint Paul's (Map: London, C 7). It is a favorite holiday resort of Londoners, contains several parks, a public librarv and branches, museiun. and public baths. The' administration is progressive and provides artisans' dwellings, cottage allotments, etc. Population, in 18111, 44..r23 ; in 1901. 72,000. HORN-SNAKE. .See Hoop-Sn-.^ice. HORNSTONE. A variety of quartz, resem- bling Hint, but more brittle, and having a struc- ture that is more splintery. See Quartz. HORNTAIL. One of a group of hymcnop- ternus insects forming the superfaiuily Siricoidea, ranked by early writers as a scries — Xylophaga, (he wood-eaters. They are distinguished from the sawllies by the fact that the fore shanks have only one spur at the tip instead of two. They are called 'horntails' because the end of the body
