H O P H O R N E T. 



The species of Southern Africa is smaller than that 

 now mentioned, its body is nearly black all over, and 

 its length is only nineteen inches. It occurs in India 



769 



as well as in Africa ; and there are some birds there 

 which seem to connect the hoopoes with the bee- 

 eaters, but their manners are little known. 



HOP is the Hiunulus lupulus of Linnaeus, a useful 

 and well known British agricultural plant. See Hu- 

 MULUS. 



HORDEUM (Linnaeus). H. vulgare is the well 

 known barley, one of the most useful of the cereals. 

 The cultivation of barley is one of the principal ob- 

 jects of British agriculture, and is of vast importance 

 to the state as well as to the community at large. A 

 large revenue is derived from the manufacture of the 

 grain into malt, whence is drawn the favourite bever- 

 age as well as the destructive spirituous liquors of the 

 people. A fourth or a fifth of every well managed 

 farm of light land is annually sown with this grain, as 

 the straw is an excellent winter fodder for cattle. 

 Heavy clayey soils are not suited to barley, as it can 

 with difficulty be got fine enough for the reception of 

 the seed. March and April are the months for sowing ; 

 and when laid in in a proper manner, that is in soil 

 perfectly pulverised, dry, and warm, the crop is ripe 

 in nine or ten weeks. There are several varieties of 

 barley in cultivation ; but the flat-eared sort (that is 

 when two opposite ranks of the spike are abortive) is 

 the most esteemed. An average crop is from three 

 to four quarters, or about thirty bushels per acre. 



HOREHOUND is the Marrubium alyssum of 

 Linnaeus. A well known medicinal herb belonging 

 to LahiaUc. An infusion of the leaves has been found 

 serviceable in chronic catarrh, and humeral asthma, 

 and made into a syrup or confection, or candied with 

 sugar they form a popular remedy for slight coughs ; 

 and though not used much professionally, they appear 

 to deserve more attention than they now receive. 



HuRI A (Fabricius). A genus of exotic coleopte- 

 rous insects, belonging to the section Heteromera, and 

 subsection Trachelides, having the jaws pointed at the 

 tip, the cks denticulated, with a long bristle attached 

 beneath each ; the antennae filiform, and the hind legs 

 often very thick. This genus is the type of one of 

 the families into which the Trachelides is divided by 

 Latreille. The species are of moderate size ; the 

 larva?, according to a Memoir by Mr. Guilding, in the 

 Linnacan Transactions, destroy those of a large species 

 of carpenter-bee (Xylocopa), the female of which 



NAT. HIST. VOL. II. 



pierces the trunks of dry dead trees, and then makes 

 her cells. The larva? of the beetle is also found in 

 the same situations, where it devours the food pre- 

 pared for the bee-grub, and thus causes the latter to 

 perish. 



HORNBEAM is the Cnrpinus betulus of Linnaeus, 

 the common hornbeam of British woods, belonging to 

 the natural order Anicntaccee. The tree is raised from 

 seed, and is a very striking plant in forest scenery. 

 The timber is much used in the construction of rustic 

 implements of husbandry, especially yokes for cattle, 

 whence its name ; its catkins are sai'd to be sometimes 

 fraudulently mixed with hops. 



HORNBLENDE. This mineral forms a very 

 important constituent in the granitic masses which 

 appear to form the giant ribs of our globe. It is of a 

 greenish black colour, and consists of silica and alu- 

 mina with magnesia. Its peculiar tint is principally 

 derived from oxide of iron, of which it contains from 

 twenty to thirty per cent. Hornblende sometimes 

 passes into mica; and if the component parts of the 

 two bodies be compared by chemical analysis, the 

 principal difference will generally be found to consist 

 in the hornblende containing the largest proportion 

 of iron. Those granitic chains which contain the 

 largest quantities of hornblende, usually split into im- 

 mense blocks, separated from each other by natural 

 seams, and appearing like the ruins of edifices con- 



structed by a race of Titans. The crystalline 

 character of this mineral is delineated in the above 

 diagrams. 



HORNET. The largest Hymenopterous insect 

 found in England, belonging to the section Acu/eata, 

 sub-section Diploptera, of Latreille, and family of 

 the wasps, Vespidee, being systematically known by 

 the name of Vcspa crabro. This insect, of which the 

 females are fourteen lines long and the males and 

 workers eleven, is of a rich red-brown colour, with 

 darker markings upon the thorax ; the head and abdo- 

 men buff coloured ; the basal segment (except the 

 posterior margin), half of the second segment, and a 

 triple series of spots on the following segments, brown. 

 The nest of this insect is in its general construction 

 similar to that of the wasp, although of coarser mate- 

 rials, and the columns supporting the layers of cells 

 much stronger. It is constructed either in the hol- 

 lows of rotten trees, such as willows, poplars, or old 

 oaks, or in the thatch, or under the eaves of barns, 

 and not unfrequently in timber-yards and other simi- 

 lar situations. It is difficult to obtain a sight of their 

 proceedings whilst building ; for if the aperture by 

 which they approach to it be too large, they lessen 

 it with a wall of the same material as their cells are 

 composed of, and which, according to Kirby and 

 Spence, consists of decayed wood, but, according to 

 CC C 



