AQtl 



ARA 



gtam. filaments ten, alternating with the 

 clefts of the nectary ; anthers oblong, ver- 

 satile ; pist. germ ovate, superior ; style, 

 none ; stigma, simple ; per. capsule on a 

 very short pedicle, obovate, woody, two- 

 celled, two valved, with the partition con- 

 trary, and bipartite ; seeds solitary, ob- 

 long. There is but one species. Aquilaria 

 ovata; leaves alternate, ovate mucronate. 

 This is a large tree covered with greyish 

 bark. Its leaves are entire, smooth vein- 

 ed, about eight inches long, and stand 

 on short hairy foot-stalks. The flowers 

 terminate the branches, on many-flower- 

 ed peduncles. A native of the mountains 

 of Malacca and Cochin-China. The wood 

 of this tree has been long used as a per- 

 fume ; and was formerly an article of the 

 materia medica under the name of agal- 

 lochum, lignum aloes, or aloes wood. 

 This wood in its natural state is white 

 and inodorous. That which possesses the 

 peculiar aroma, for which it is valued, 

 is supposed to be the consequence of a 

 diseased process in the tree, causing the 

 oleaginous particles to stagnate and con- 

 crete into a resin in the inner parts of the 

 trunk and branches, by which the natural 

 appearance of the wood is altered, so as 

 to become of a darker colour and of a fra- 

 grant smell. At length the tree dies, and 

 when splitten, the resinous part is taken 

 out. The perfumes which this wood af- 

 fords are highly esteemed by the oriental 

 nations ; and from the bark of the tree is 

 made the common paper which the Co- 

 chin-Chinese use for writing ; in the same 

 manner the Japanese make use of the 

 bark of a species of mulberry (morus pa- 

 pyrifera.) This perfume is said to be 

 useful in vertigo and palsy : given in the 

 form of powder, it is recommended to 

 restrain vomitings and alvine fluxes. To 

 us, however, it seems to contain little else 

 than that camphoraceous matter common 

 to many other vegetable substances. 

 From its bitter taste it has the name of 

 aloes, although no otherwise allied to it. 

 AQUILEGIA, columbine, in botany a 

 genus of the Polyandria Pentagynia class 

 of plants, having no calyx ; the corolla 

 consists of five plane, patent, equal petals, 

 of a lanceolate, ovate figure; the nectaria 

 are five in number; they are equal, and 

 stand alternately with the petals ; the 

 fruit consists of five straight, parallel, cy- 

 lindric, accumulated capsules, each of 

 which consists of a single valve. The 

 seeds are numerous, oval, carinated, and 

 adhere to the suture. There are five 

 species. 



ARA, in astronomy, a southern con- 

 stellation, consisting of eight stars. 



ARAB1S, in botany, -wall-cross, a genus 

 of the Tetradinamia Siliquosa class of 

 plants, the calyx of which is a deciduous 

 perianthium, consisting of four ovato-ob- 

 iong, acute, gibbous, concave leaves; the 

 corolla consists of four oval, patent, cruci- 

 form petals; the fruit is a very long com- 

 pressed pod, containing several roundish 

 compressed seeds. There are twenty-one 

 species. 



ARACHIS, in botany, ground-nut, a ge- 

 nus of the Diadelphia Decandria class of 

 plants, the flower of which is papilionace- 

 ous, and consists of three petals ; and its 

 fruit is an oblongunilocular pod, contract- 

 ed in the middle, and containing two ob- 

 long, obtuse, and gibbous seeds. There 

 is but one species, found in the Inches, a 

 tree, stem herbaceous, haiiy, procum- 

 bent. The branches trail on the ground, 

 and the germ, after flowering," thrusts it- 

 self under ground, where the food is form- 

 ed and ripened. 



ARACHNO1DES, in zoology, a name 

 given to those echini marini, or sea-hedge- 

 hogs, which are of a circular form, but 

 variously indented at the edges. See 

 ECHINUS. 



ARALIA, berry-bearing angelica, in bo- 

 tany, a genus of the Pentandria Pentagy- 

 nia class of plants, the flowers of which 

 are collected into an umbel, of a globose 

 figure, with a very small involucrum ; the 

 perianthium is very small, divided into 

 five parts, and placed on thegermen: the 

 corolla consists of five ovato-acute, ses- 

 sile, reflex petals; the fruit is a roundish, 

 coronated, striated berry ; having five 

 cells : the seeds are single, hard, and ob- 

 long. There are four divisions, viz. A. 

 leaves entire ; B. leaves lobed ; C. leavei 

 in finger-like divisions; D. leaves decom- 

 pound, and more than decompound. In 

 the first there are three species ; in the 

 second one ; in the third two ; and in the 

 fourth four. 



ARANE A, in natural history, the spider, 

 a genus of insects of the order Aptera. 

 Gen. char, legs eight; eyes eight, some- 

 times six ; mouth furnished with two 

 hooks, or holders ; feelers two, jointed,, 

 the tips of which in the mule distinguish 

 the sex ; abdomen terminated by papillx, 

 or teats, through which the insect draws 

 the thread. 



One of the largest of the European spi- 

 ders is the Aranea diadema of .Linnaeus, 

 which is extremely common in England^ 

 and is chiefly seen during the autumnal 



