order of dicotyledonous plants, the species of which are herbs, shrubs, vines, and trees, mostly with a copious, milky juice. The leaves are mostly opposite, entire, and without stipules. The flowers are five-parted; ovary single and two-celled, or two and cone-celled. Fruit, a follicle or drupe; seeds with a straight embryo; endosperm small or none; seed often covered with a thistle-like down. There are about 130 genera and more than 1000 species in this order, the principal subdivisions of which are: Arduineæ, represented by Arduina and Laedolphia; Plumerieæ, containing the tropical genus Tabernæmontana, and Aspidiosperma, Vinca, and Alstonia; and Echitideæ, which embraces Kickxia, Apocynum, Nerium, and Strophanthus. The properties of plants of this order vary greatly, but many are exceedingly poisonous. Some, like Kickxia and Landolphia, are rich in caoutchoue; Apocynum yields valuable bast fibre, and its rhizomes are used in medicine; Strophanthus contains in its seed a powerful poisonous alkaloid; while others have varied economic uses. See Periwinkle; Oleander; Indian Hemp; Rubber; Strophanthus; Dogbane; Wrightia; Poisonous Plants, etc.
APOCYNUM, ȧ-pŏs'ĭ-nŭm. A genus of plants. See Dogbane.
APOCYNUM, ȧ-pŏs'ĭ-nŭm. A drug composed of the powdered root of Apocynum cannabinum, Canadian or Indian hemp. Its taste is acrid and bitter. It contains apocynine, gallic and tannic acids, a bitter principle, etc. Its active ingredients are soluble in water and alcohol. Moderate doses increase the secretions of the skin, bronchi, and kidneys. Large doses cause vomiting and purging. The chief use of apocynum is as a diuretic. It may act directly as a renal stimulant and dilate the arterioles, but probably chiefly by increasing artificial pressure. It fails in many cases, but in others it causes marked increase of urine. See Apocynaceæ; Dogbane.
APODES, ăp'ṓ-dēz (Gk. ἀ, a, priv. + πούς, pous, foot). An order of teleost fishes, variously limited, including the eels (not the electric eel), murænas, and allied serpentiform species. Consult T. Gill, Standard Natural History, III., 100 (Boston, 1885). See Eel.
APODICTIC (Gk. ἀποδεικτικός, apodeiktikos,
demonstrating, -ive). A logical term signifying
necessary, and applied to judgments which
admit of no contradiction. It is used largely by
Kant. See A Priori.
APOG'AMY (Gk. i-rS, apo, away from + 7(£;Uos, ganios, a wedding). A name which refers to the fact that a plant which ordinarily comes from a fertilized egg may, under certain conditions, develop in some other way. It is a general term, used to cover all cases in which
the asexual plant does not come from a fertilized egg, without reference to the method of its origin. 'Parthenogenesis' is that form of apogamy in which a plant is developed from an egg that has not been fertilized. In other cases of apogamy the new plant is developed in a vegetative way from various other tissues. The phenomenon of apogamy has been observed chiefly among
the ferns, which seem to respond most readily
to the conditions which favor it. Numerous
cases have now been observed (both among
native and cultivated forms), in which the leafy
plant arises in various ways directly from the
prothallium, without the fertilization or even
production of an egg. Among the mosses apog-
amy has never been observed; that is, there is
no reason to believe that the spore-bearing struc-
ture ever has any other origin than a fertilized
egg. Among the seed-plants the phenomenon
has been recorded in a nifmber of cases, and has
usually been wrongly referred to parthenogene-
sis. So far as the records go, true partheno-
genesis has been established in .seed-plants only
for Antennaria and Alehemilla, genera of Com-
posita', and for Thalictrum, a genus of Ranuncu-
lacea!. In various other cases, however, in wliieh
embryos are known to arise in seeds which have
received nothing from the pollen, it is discov-
ered that the embryo is not developed by the
unfertilized egg, but arises vegetatively irom va-
rious tissues of the ovule, just as a bud may
develop almost anywhere upon a plant. The
fact that a seed contains an embryo is not sure
indication that this embryo has developed from
the egg. In seed-plants, therefore, the extent
of the phenomenon of apogamy is uncertain and
difficult to determine.
AP'OGEE (Gk. dxA. apo, from, + yij, ge, the earth). When the earth and some other planet reach such positions in their respective orbits that the distance between them is a maximum, then that planet is said to be in its apogee. The use of the word apogee is usually restricted to the sun and moon, the sun's apogee corresponding to the earth's aphelion, and the moon's apogee being the point of its orbit most remote from the earth. Apogee is opposed to perigee.
AP'OGEOT'ROPISM, or Negative Geo-TROPISM. That form of sensitiveness to gravity in plants by virtue of which organs tend to grow vertically upward — that is, in a direction opposite to that of the earth's attraction. The best example of this phenomenon is found in the main shoots of most plants. Wlien 'cen- trifiigal force' is brought to bear upon the plant in place of gravity, the stems of seedlings grow toward the centre of revolution, while the roots, being positively geotropic, grow in the opposite direction. See Geotropism in Plants.
APOLDA, a-pril'da. A town of the Grand Duchy of Saxe-Weimar, Germany, near the Ilm, a feeder of the Saale, eight miles northeast of Weimar ( Jlap : Germany. D 3 ) . It is a station on the Thuringian Railway, between Weimar and Weissenfels. It is a place of much industrial activity, having extensive manufactures of ho- sierv and woven goods. Population, in 1895, 20.798; in 1900, 20,352.
APOLLINA'RIS ( ? -392). The younger, bishop of Laodicca in Syria, and one of the warmest opponents of Ariaiiism. Both as a man and a scholar he was held in the greatest reverence, and his writings were extensively read in his own day. His father, Apollinaris the elder, who was Bishop of Laodicea, was born at Alexandria, and taught grammar, first at Berytus, and afterward at Laodicea. When Julian prohibited the Christians from teaching the classics, the father and son endeavored to supply the loss by converting the Scriptures into a body of poetry, rhetoric, and philosophy. The Old Testament was selected as the subject for poetical compositions after the manner of Homer, Pindar, and the tragedians; while the New Testament formed the groundwork of dia-
