AQUILA. 



ARACHNIDA. 



tho shooU or by wed* The stove ipeciei should be grown in n 

 uiixture of lomni and peat, ainl cuttinpi will root freely in sand, under 

 hand-glass. Most of the species of Aquifoliaoeous I'Unta may be 

 cultivated in the name manner. 



(Don, OunleiKrt Didioiuiry ; Burnett, Outliiut of Botany ; Limller, 

 .\\itnral Syftrm.) 



AQUILA, the generic niuuo of the Eagles. (FALCOXIDJC.) 



AyriLAKIAX'K.K, Ai/tiUariadt, a small natural order of plants 

 belonging to the Incomplete Kxogeiw. The species are tree* with 

 smooth branches and a tough bark. The leaves are alternate, entire, 

 eated on abort stalks without stipule*, and when full-grown are 

 rauooth and shiny, with very fine veins running together into a mar- 

 ginal win just within the margin. The calyx is turbiuato or tubular, 

 limb 5-cleft, MgmenU spreading, persistent, with an imbricated 

 Mtivation, the orifice furnished with 5- or 10-bearded scales (meta- 

 morphosed stamens). The stamens are 5 or 10 in number ; when 5, 

 they are opposite the segments of the calyx ; the filaments are short 

 or absent, smooth, inserted into the orifice of the calyx a little lower 

 down than the scales, except in cases where they are united to the 

 tube of the calyx ; the anthers are narrow, oblong, attached by their 

 back below the middle, 2-celled, opening internally un'd lengthwise ; 

 the ovary is superior, sessile or stipitute, downy, compressed, 1 -celled, 

 having internally, upon each flattened side, a linear prominent placenta 

 resembling a dissepiment, hence spuriously 2-celled, with a very 

 narrow partition ; ovules two, of which one is suspended from each 

 placenta, tapering downwards ; the style is either absent or conical 

 and thread-shaped ; the stigma is simple and large; the fruit is a 

 capsule, pear-shaped, compressed, sessile or stipitate, 1 -celled, 2-valved, 

 the valves bearing in the middle the placenta:, which almost touch 

 each other. One seed is mostly borne on each placenta (one is some- 

 times abortive) ; the seed rises up by aid of a funiculus. originating 

 near the apex of the placenta, and is furnished with a tail-like aril, 

 which descends straight fn mi the hilnin to the bottom of the capsule ; 

 the radicle is straight and superior, the albumen is absent, and the 

 cotyledons thick, fleshy, and hemispherical. 



TUi order, which consists at present of only three genera, was 

 constituted by Robert Brown, who regarded it as having so close an 

 affinity with UhailUtaceic as to see no objection to making it a section 

 of that order. He also pointed out its relation to Thymtlacece, in 

 which he in followed by Lindley, who says, " Aqutiariacea; chiefly 

 differ from Thymelacat in their dehiscent fruit, nud probably also in 

 the direction of their radicle. In both orders the ovary is superior 

 and 1 -celled ; both have similar scale-like bodies at the orifice of the 

 calyx, and no petals ; both suspended ovules, a single style, and 

 capitate stigma." De Candollo places the order between C/iaillctacc(e 

 and Trreltntarne. 



All the species of A quilariacat are natives of the East Indies. 



The three genera of this order are A ijuilaria, Opkiotpermum, and 

 Gyrituti*. Of the last two little is known. One species of each has 

 been described. There are three species of Ar/uilai-iu. 



A. Malacceiuit, the Suit (TAigU, or Eagle-Wood, is a native of 

 Malacca, and produces a whitish-yellow wood. This is the ,1 

 of some botanists. A. Agallwhum is a native of the East Indies, 

 where it is called Ugoor, or Ugooroo, by the natives, and Lignum- 

 Aloes, or Aloe- Wood, by the Europeans. The wood has a fine scent, 

 and is supposed to be the Calambac, or Agallochum, of the ancients. 



A. teeundaria is another species which also yields a scented wood, 

 and has been known in the Mntcrin Mcdica, and used in perfumery, 

 under the names of Agallochum, Lignum- Aloes, and Aloe- Wood. In a 

 healthy state this wood is said to be white and inodorous ; but it is 

 subject to the attacks of disease, which causes the secretion of a 

 resinous matter, and the wood then becomes coloured, and gives out 

 n |i<>werful scent This secretion resembles camphor in many of its 

 properties, and has a bitter flavour: hence the name Aloe- Wood. In 

 medicine it is recommended in the same diseases as the fetid resins 

 and volatile oil*, and does not seem to possess peculiar properties ; so 

 that it is not used as a medicine in Europe. The Cochin-Chinese are 

 said to make their paper from the bark of this or some kindred I 

 if A '/uilaria. These trees must not be confounded with the A loejylon 

 AgaJiii<-hum, or Aloe-Wood, which is a tree belonging to the natural 

 order Jsynmtiiottr, and which also yields a scented wood used by the 

 Chineoe in medicine and perfumery. 



(Don, (I'anUner'i Dictionary; Lindley, KcUural System; Royle, 

 llliutratiotu.) 



AQl'll.i: <:\.\, literally the Water-Gatherer, because the leaves 

 r-iIl.Tl waU-r in tli.-ir hollow, is a small genus of planto, commonly 

 called Columbines, belonging to the order Kan unculacnr. !' \\lu.-ii 

 several species are cultivated in gardens. They are known from 

 '1,1, to which they are the most nearly related, by the leaves of 

 the calyx being all of the same form and size, and by the petals 

 having each a long curved horn or spur at the tmsu. All the species 

 are handsome perennials, easily propagated by dividing the crown of 

 their roots : the commonest, hence named A. rulyarit, i- found in 

 woods and thickets in this and all other parts of Europe ; it lias pro- 

 duced many varieties, differing in the colour of the flowers, and in 

 tin- multiplication of the petals, for the sake of which it i* eonunonly 

 cultivated. The other species are found cither in the north of Asia, 



..r in N..rth America. They are all acrid plants, but much inferior 

 to Aconito in their medicinal projwrtiM; hence little attention has boon 

 given to them. 



A'KACH IS, a genus of plants belonging to the natural order Leynnii- 

 HOtte. One species, A. kypogm, is called the Earth-Nut. The < , 

 stance by which the Arathit hyiioyira is particularly remarkable is tho 

 manner in which its fruit is produced. Instead of hanging down from 

 among the leaves in the manner of other plants, this conceals itsulf in 

 the earth, in which it is deeply buried at tin- |-ri.l whi-n it becomes 

 ripe, a phenomenon which hnpjx'n-i thin: Tin- young fniit, instead 

 of U-ing placed at the bottom of the calyx, as in other kinds of 

 is found at the bottom anil in the inside of u long slender tulw, h h 

 looks like a flower-stalk. When the flower has withered, and the young 

 fruit is fertilised, nothing but the bottom of this tube with its .- 

 remains. At this period a small point projects from the summit ,.t tie- 

 young fruit, and gradually elongates, curving downwards toward.- the 

 earth. At the some time the stalk of the fruit lengthens, until >!..- 

 small point strikes the earth, into which the now half-grown fniit is 

 speedily forced, and where it finally rijMins in what would seem n moht 

 unnatural position. When mature, it is a pale-yellow wrinkled oblong 

 pod, often contracted in the middle, and containing two or three seeds 

 the size of a hazel-nut. These are considered a valuable article of food 

 in Africa and the tropical parts of Asia and America. In flavour the 

 nuts are as sweet as on almond ; and they yield, when pressed, an oil 

 in no respect inferior to that of olives. 



The plant will only grow in a light sandy soil, in which its pods can 

 readily be buried, and it requires a climate as hot at least as that of 

 the south of France. Its stems grow from one to two feet high ; its 

 leaves are composed of four broad and blunt leaflets ; and its flowers 

 are small and of a pale yellow colour. 



AKA'CHNIDA, a class of animals including Spiders, Mites, and 

 Scorpions, all ranked by Linmuus under Insects, but whU-h arr \>iv 

 properly separated from them, on account of external form, structure, 

 and habits. The separation was first made, we believe, by Kabiiciim, 

 who, looking chiefly to the structure of the mouth, characterised the 

 greater number of the animals now ranked under Arachnitis, l>y the 

 jaws (maj-illa) being homy and furnished with a claw (H>//II). M. 

 Lamarck afterwards made the Amclinuln a distinct class; but we owe 

 to M. Latreille and Dr. Leach the establishment of characters more 

 precise, and extending to a greater number of genera. Much has been 

 done in perfecting the knowledge of their structure, manners, and 

 numerous species by Clerck, De Geer, Walckeuoer, Trevinuiux. 

 Dufuur, Herald, Straus-Diirckheim, Blackwall, and others. Wo shall 

 condense into as short a compass as we con the most important points 

 investigated by these naturalists. 



The Arachnida (Accra, Virey) differ from Insects in having no 

 antenna; ; in the eyes being in most species 8, and, even when only 

 two in number, never being placed laterally on the head ; in the legs 

 living usually 8, though in some species 6, and in others II); and in 

 their respiratory apparatus consisting of radiated trachea:, communi- 

 cating with a sort of gills inclosed in pouches in the lower jrt of the 

 abdomen. 



The skin or crust of the Arachnida is in general more leathery th.m 

 horny ; but whether it be soft, as hi most species, or hard, as in a few . 

 it performs a similar office to the bones of larger animals in giving 

 support to the soft parts and attachment to muscles, the legs !< in : ; 

 joined upon and radiating from a common breast-plate (itrrnum) 

 externally; while, according to Straus-Durckheim, there is also an 

 internal breast-plate of a gristly texture (>i :i-til<njuutvc 



inUneuf) in fonn of a horse-shoe, the two cuds of which ore directed 

 forwards. 



The greater number of the ArachniJa are carnivorous, and are 

 furnished with appropriate organs for their predatory lite. Some 

 parasitic species, such as the minute Parasite Mites (Ltpti, De < 

 which we have observed infesting numerous species of insects, from 

 tho largest butterflies to the smallest gnats, are furnished with a 

 sucker, in some respects constructed like that of the Gadfly (Tabamu). 

 In other species, there may be distinguished a pair of upper jaws 



liitla), a pair of under jaws (auuilta), carrying joi; 

 (//'/"'>. and between them a sort of tongue formed by a pro] 

 from the breast At the back port of the mouth is placed a piece of 

 a horny texture, which Savigny, Latnille, and Audoiiin term the 

 . forming the entrance into the gullet. The gullet, together 

 with a bulging on the fore port of it, termed the stomach, an well a.; 

 the intestines, nm in a straight line from the pharynx to il,. 

 Near the upjier |iortion of the gullet are found salivary vessels, 

 exterior aperture is in tho first joint of the' upper jaws. The 

 secreted by these vessels appears to be poisonous. Lower do-. 

 the liiliary vessels, which resemble those of insects. 



In the greater number of Arachnida there in a i-ompl. (< and \eiy 

 distinct eireulatory system. The heart, which differs innt^ 

 from tho dorsal vessel by some termed tin' heart, in insect.-. 



airmen, an. I its 'pulsations may be distinguished externally. 

 hiek longitudinal vessel, giving origin to a certain number of 

 arteries, and receiving veins by which the blmd returns from the 

 respiratory organs in other part.* of the liody. 



The respiratory organs have two striking peculiarities, upon which 

 M. Latrcillc founded his two great divisions of A nu 7 



