ABYSSINIAN MEAD'OW GRASS. See Meadow Grass.
ACA'CIA (literally, thorny, Gk. oK/f, akis,
point, splinter, thorn) . A genus of plants of
the order Leguminosæ, differing from Mimosa in
the greater number of stamens (10 to 200) and
the absence of transverse partitions in ihe pods.
There are about 450 species of Acacia, 300 of
which are indigenous to Australia and Polynesia.
The others are found in all tropical and sub-
tropical countries except Europe. The flowers
are small and are arranged in globular or elon-
gated clusters. The leaves are usually bipin-
nately compound; but in many of the Australian
species the leaflets are greatly reduced and the
leaf blades correspondingly enlarged and flat-
tened into what are termed phyllodia. Most of
the species having phyllodia inhabit hot. arid
regions, and this modification prevents too rapid
evaporation of moisture from the leaves. Many
of the species are of great economic importance :
some yield gums, others valuable timber, and
still others food products. The African species,
Acacia gummifera. Acacia seyal. Acacia ehrenber-
giana. Acacia tortilis, and Acacia arabica, yield
gum arable, as do the Asiatic species. Acacia
arabica and the related Albizzia lebbck. A some-
what similar gum is produced by Acacia decur-
rens and Acacia dealbata of Australia and
Acacia horrida of South Africa. Gum Senegal
is the product of Acacia verek, sometimes called
Acacia Senegal. The drug "catechu" is prepared
from Acacia catechu. The astringent bark of a
number of species is extensively used in tanning,
especially the bark of those known in Australia
as Wattles. For this purpose Acacia decurrens,
the Black Wattle, is one of the best, the air-dried
bark of this plant containing about four times
as much tanning extract as good oak bark. The
most valuable timber tree of the genus is probably the Blackwood (Acacia melanoxylon), of Australia. The tree attains a large size, and the wood is easily worked and takes a high polish. A number of the Acacias have been introduced into cultivation in Europe and America, where they thrive. The California experiment station recommends planting several species for tanning extract and for timber. A number of species are grown in mild climates and in greenhouses as ornamentals, partly because of the fragrance of their flowers. The foliage of some of the bipinnate species exhibits sleeping movements analogous to the movements of the sensitive plant. Some species show a remarkable sensitiveness to weather, the leaves remaining closed while the sky is cloudy. The common American Robinia or Locust (Robinia pseudacacia) and the Robinia hispida are known as Acacia and Rose Acacia in Europe and elsewhere. Fossil forms of Acacia are abundant in the Tertiary beds of Aix in France, and an allied genus, Acaciæphyllum, has been described from the Cretaceous beds of North America. Consult: F. von Mueller, Iconography of Australian Acacias (Melbourne); L. H. Bailey, Cyclopædia of American Horticulture (New York, 1900-01); G. Nicholson, Illustrated Dictionary of Gardening (London, 1884-89).
ACACIANS, u-ka'shi-anz. See Acasius.
ACACIUS, aka'slii-fis. Bishop of Cæsarea (340-365). He founded a sect, named after him, which maintained that the Son was like the Father; not of the same or of similar substance, but that this likeness was in the will alone. Thus he differed from the general Arian party. His doctrine was actually accepted by a synod at Constantinople, which he manipulated (359), which gave rise to Jerome's famous saying: "The whole world groaned and wondered to find itself Arian." Yet in the end, as formerly, it was condemned, and he was exiled.
AC'ADEM'IC LE'GION. A name applied particularly to an armed body of students who participated in the uprising of 1848 in Vienna; also more generally to similar student companies elsewhere in the revolutionary disturbances of that year.
ACADÉMIE DES BEAUX-ARTS, a'ka'da'-
me' da l)u'z;ir'. See Ecole des Beaux-Arts.
AC'ADE'MUS (Gk. Ἀκάδημος, Akadēmos). A mythical hero of Attica. When the Tyndaridæ invaded the Attic land to rescue Helen from the hands of Theseus, Academus revealed to them the place where their sister was hidden, and in return for this act the Lacedæmonians then and thereafter showed the hero great honor. The Academia was thought to have received its name from Academus. though the earlier form, Hecademia, seems to point to an original Hecademus. The Academia was in early times a sacred precinct, six stades northwest of the Dipylon gate of Athens. Later a gymnasium was built in the precinct, and still later the spot was made a public park, being planted with many kinds of trees, adorned with statues, watered by the Cephissus, and laid out in walks and lawns. Here, in the gymnasium and the neighboring walks, Plato conversed with his pupils and held his first formal lectures in philosophy. Later, having purchased in the neighborhood a piece of land and built thereon a temple to the Muses and a lecture-hall, he transferred his school thither. This spot was also called Academia, and gave its name to the school.
ACAD'EMY (Gk. ἀκαδήμεια, akadēmeia, or ἀκαδημία, akadēmia). Originally the name of a public garden outside of Athens, dedicated to Athene and other deities, and containing a grove and a gymnasium. It was popularly believed to have derived its name from its early owner, a certain Academus, an eponymous hero of the Trojan War. It was in these gardens that Plato met and taught his followers, and his school came to be known from their place of meeting as the Academy. The later schools of philosophy which developed from the teachings of Plato down to the time of Cicero were also known as academies. Cicero himself and many of the best authorities following him reckoned but two Academies, the Old, founded by Plato (428-348 B.C.), and including Speusippus. Xenocrates of Chalcedon, Polemo, Crates, and Cranto; and the New, founded by Arcesilaus (241 or 240 B.C.). Others have, however, reckoned the latter as the Middle Academy, and added a third, the New Academy, founded by Carneades (214-129? B.C). Others again have counted no fewer than five, adding to the three above a fourth, that of Philo, and a fifth, that of Antiochus. (See articles Plato; Arcesilaus; Carneades; Philosophy; and references under the last.) From its use in the sense of a school the word academy has come to be applied to certain kinds of institutions of learning; from its use in the sense of a body of learned men it has come to
