[1] In 1906 Pierre Marie of Paris expressed views (_La Semaine
medicale_, May 23 and October 17, and elsewhere) upon the question of
aphasia which have given rise to much animated controversy, since
they are in many respects at complete variance with the classical
conception which has been represented in the present article. Marie
holds that Broca's convolution plays no special role in the function
of speech. He admits that a lesion in the region of the lenticular
nucleus is followed by inability to speak, but this defect is, in his
opinion, to be regarded as an anarthria. He further admits the
production of sensory aphasia--the aphasia of Wernicke, as he prefers
to call it after its discoverer--by lesions which destroy the angular
and supramarginal gyri, and the upper two temporo-sphenoidal
convolutions, but he regards the essential foundation of sensory
aphasia as a diminution of intelligence. There are, in his opinion,
no sensory images of language. Motor aphasia is, he believes, nothing
more than a combination of sensory aphasia and anarthria. These
conclusions have been vigorously attacked, more especially by
Dejerine of Paris (_La Presse medicale_, July 1906 and elsewhere).
APHELION (from Gr. [Greek: apo], from, and [Greek: helios], sun), in
astronomy, that point of the orbit of a planet at which it is most
distant from the sun. Apogee, Apocentre, Aposaturnium, &c. are terms
applied to those points of the orbit of a body moving around a centre of
force--as the Earth, Saturn, &c.--at which it is farthest from the
central body.
APHEMIA (from Gr. [Greek: a], without, and [Greek: pheme], speech), in
pathology, the loss of the power of speech (see APHASIA).
APHIDES (pl. of Aphis), minute insects, also known as "plant-lice,"
"blight," and "green-fly," belonging to the homopterous division of the
order Hemiptera, with long antennae and legs, two-jointed, two-clawed
tarsi, and usually a pair of abdominal tubes through which a waxy
secretion is exuded. These tubes were formerly supposed to secrete the
sweet substance known as "honey-dew" so much sought after by ants; but
this is now known to come from the alimentary canal. Both winged and
wingless forms of both sexes occur, and the wings when present are
normal in number, that is to say two pairs. Apart from their importance
from the economic standpoint, Aphides are chiefly remarkable for the
phenomena connected with the propagation of the species. The following
brief summary of what takes place in the plant-louse of the rose (_Aphis
rosae_), may be regarded as typical of the family, though exceptions
occur in other species: Eggs produced in the autumn by fertilized
females remain on the plant through the winter and hatching in the
spring give rise to female individuals which may be winged or wingless.
From these females are born parthenogenetically, that is to say without
the intervention of males, and by a process that has been compared to
internal budding, large numbers of young resembling their parents in
every particular except size, which themselves reproduce their kind in
the same way. This process continues throughout the summer, generation
after generation being produced until the number of descendants from a
single individual of the spring-hatched brood may amount to very many
thousands. In the autumn winged males appear, union between the sexes
takes place and the females lay the fertilized eggs which are destined
to carry the species through the cold months of winter. If, however, the
food-plant is grown in a conservatory where protection against cold is
afforded, the aphides may go on reproducing agamogenetically without
cessation for many years together. Not the least interesting features
connected with this strange life-history are the facts that the young
may be born by the oviparous or viviparous methods and either
gamogenetically or agamogenetically, and may develop into winged forms
or remain wingless, and that the males only appear in any number at the
close of the season. Although the factors which determine these
phenomena are not clearly understood, it is believed that the appearance
of the males is connected with the increasing cold of autumn and the
growing scarcity of food, and that the birth of winged females is
similarly associated with decrease in the quantity or vitiation of the
quality of the nourishment imbibed. Sometimes the winged females migrate
from the plant they were born on to start fresh colonies on others often
of quite a different kind. Thus the apple blight (_Aphis mali_) after
producing many generations of apterous females on its typical food-plant
gives rise to winged forms which fly away and settle upon grass or
corn-stalks.
Closely related to the typical aphides is _Phylloxera vastatrix_, the
insect which causes enormous loss by attacking the leaves and roots of
vines. Its life-history is somewhat similar to that of _Aphis rosae_
summarized above. In the autumn a single fertile egg is laid by apterous
females in a crevice of the bark of the vine where it is protected
during the winter. From this egg in the spring emerges an apterous
female who makes a gall in the new leaf and lays therein a large number
of eggs. Some of the apterous young that are hatched from these form
fresh galls and continue to multiply in the leaves, others descend to
the root of the plant, becoming what are known as root-forms. These,
like the parent form of spring, reproduce parthenogenetically, giving
rise to generation after generation of egg-laying individuals. In the
course of the summer, from some of these eggs are hatched females which
acquire wings and lay eggs from which wingless males and females are
born. From the union of the sexes comes the fertile egg from which the
parent form of spring is hatched.
See generally G.B. Buckton, _British Aphides_ (Ray Soc. 1876-1883);
also ECONOMIC ENTOMOLOGY. (R. I. P.)
APHORISM (from the Gr. [Greek: aphorizein], to define), literally a
distinction or a definition, a term used to describe a principle
expressed tersely in a few telling words or any general truth conveyed
in a short and pithy sentence, in such a way that when once heard it is
unlikely to pass from the memory. The name was first used in the
_Aphorisms_ of Hippocrates, a long series of propositions concerning the
symptoms and diagnosis of disease and the art of healing and medicine.
The term came to be applied later to other sententious statements of
physical science, and later still to statements of all kinds of
principles. Care must be taken not to confound _aphorisms_ with
_axioms_. Aphorisms came into being as the result of experience, whereas
axioms are self-evident truths, requiring no proof, and appertain to
pure reason. Aphorisms have been especially used in dealing with
subjects to which no methodical or scientific treatment was applied till
late, such as art, agriculture, medicine, jurisprudence and politics.
The _Aphorisms_ of Hippocrates form far the most celebrated as well as
the earliest collection of the kind, and it may be interesting to quote
a few examples. "Old men support abstinence well: people of a ripe age
less well: young folk badly, and children less well than all the rest,
particularly those of them who are very lively." "Those who are very fat
by nature are more exposed to die suddenly than those who are thin."
"Those who eject foaming blood, eject it from the lung." "When two
illnesses arrive at the same time, the stronger silences the weaker."
The first aphorism, perhaps the best known of all, which serves as a
kind of introduction to the book, runs as follows:--"Life is short, art
is long, opportunity fugitive, experimenting dangerous, reasoning
difficult: it is necessary not only to do oneself what is right, but
also to be seconded by the patient, by those who attend him, by external
circumstances." Another famous collection of aphorisms is that of the
school of Salerno in Latin verse, in which Joannes de Meditano, one of
the most celebrated doctors of the school of medicine of Salerno, has
summed up the precepts of this school. The book was dedicated to a king
of England. It is a disputed point as to which king, some authorities
dating the publication as at 1066, others assigning a later date. The
dedication gives the following excellent advice:--
"Anglorum regi scribit schola tota Salernae.
Si vis incolumem, si vis te reddere sanum,
Curas tolle graves: irasci crede profanum:
Parce mero: coenato parum; non sit tibi vanum
Surgere post epulas: somnum fuge meridianum:
Ne mictum retine, nec comprime fortiter anum:
Haec bene si serves, tu longo tempore vives."
Another collection of aphorisms, also medical and also in Latin, is that
of the Dutchman Hermann Boerhaave, published at Leiden in the year 1709;
it gives a terse summary of the medical knowledge prevailing at the
time, and is of great interest to the student of the history of
medicine.
APHRAATES (a Greek form of the Persian name Aphrahat or Pharhadh), a
Syriac writer belonging to the middle of the 4th century A.D., who
composed a series of twenty-three expositions or homilies on points of
Christian doctrine and practice. The first ten were written in 337, the
following twelve in 344, and the last in 345.[1] The author was early
known as _hakkima pharsaya_ ("the Persian sage"), was a subject of Sapor
II., and was probably of heathen parentage and himself a convert from
heathenism. He seems at some time in his life to have assumed the name
of Jacob, and is so entitled in the colophon to a MS. of A.D. 512 which
contains twelve of his homilies. Hence he was already by Gennadius of
Marseilles (before 496) confused with Jacob, bishop of Nisibis; and the
ancient Armenian version of nineteen of the homilies has been published
under this latter name. But (1) Jacob of Nisibis, who attended the
council of Nicaea, died in 338; and (2) our author, being a Persian
subject, cannot have lived at Nisibis, which became Persian only by
Jovian's treaty of 363. That his name was Aphrahat or Pharhadh we learn
from comparatively late writers--Bar Bahlul (10th century), Elias of
Nisibis (11th), Bar-Hebraeus, and 'Abhd-isho'. George, bishop of the
Arabs, writing in A.D. 714 to a friend who had sent him a series of
questions about the "Persian sage," confesses ignorance of his name,
home and rank, but infers from his homilies that he was a monk, and of
high esteem among the clergy. The fact that in 344 he was selected to
draw up a circular letter from a council of bishops and other clergy to
the churches of Seleucia and Ctesiphon and elsewhere--included in our
collection as homily 14--is held by Dr W. Wright and others to prove
that he was a bishop. According to a marginal note in a 14th-century MS.
(B.M. Orient. 1017), he was "bishop of Mar Mattai," a famous monastery
near Mosul, but it is unlikely that this institution existed so early.
The homilies of Aphraates are intended to form, as Professor Burkitt has
shown, "a full and ordered exposition of the Christian faith." The
standpoint is that of the Syriac-speaking church, before it was touched
by the Arian controversy. Beginning with faith as the foundation, the
writer proceeds to build up the Structure of doctrine and duty. The
first ten homilies, which form one division completed in 337, are
without polemical reference; their subjects are faith, love, fasting,
prayer, wars (a somewhat mysterious setting forth of the conflict
between Rome and Persia under the imagery of Daniel), the sons of the
covenant (monks or ascetics), penitents, the resurrection, humility,
pastors. Those numbered 11-22, written in 344, are almost all directed
against the Jews; the subjects are circumcision, passover, the sabbath,
persuasion (the encyclical letter referred to above), distinction of
meats, the substitution of the Gentiles for the Jews, that Christ is the
Son of God, virginity and holiness, whether the Jews have been finally
rejected or are yet to be restored, provision for the poor, persecution,
death and the last times. The 23rd homily, on the "grape kernel" (Is.
lxv. 8), written in 344, forms an appendix on the Messianic fulfilment
of prophecy, together with a treatment of the chronology from Adam to
Christ. Aphraates impresses a reader favourably by his moral
earnestness, his guilelessness, his moderation in controversy, the
simplicity of his style and language, his saturation with the ideas and
words of Scripture. On the other hand, he is full of cumbrous
repetition, he lacks precision in argument and is prone to digression,
his quotations from Scripture are often inappropriate, and he is greatly
influenced by Jewish exegesis. He is particularly fond of arguments
about numbers. How wholly he and his surroundings were untouched by the
Arian conflict may be judged from the 17th homily--"that Christ is the
Son of God." He argues that, as the name "God" or "Son of God" was given
in the O.T. to men who were worthy, and as God does not withhold from
men a share in His attributes--such as sovereignty and fatherhood--it
was fitting that Christ who has wrought salvation for mankind should
obtain this highest name. From the frequency of his quotations,
Aphraates is a specially important witness to the form in which the
Gospels were read in the Syriac church in his day; Zahn and others have
shown that he--mainly at least--used the _Diatessaron_. Finally, he
bears important contemporary witness to the sufferings of the Christian
church in Persia under Sapor (Shapur) II. as well as the moral evils
which had infected the church, to the sympathy of Persian Christians
with the cause of the Roman empire, to the condition of early monastic
institutions, to the practice of the Syriac church in regard to Easter,
&c.
Editions by W. Wright (London, 1869), and J. Parisot (with Latin
translation, Paris, 1894); the ancient Armenian version of 19 homilies
edited, translated into Latin, and annotated by Antonelli (Rome,
1756). Besides translations of particular homilies by G. Bickell and
E.W. Budge, the whole have been translated by G. Bert (Leipzig, 1888).
Cf. also C.J.F. Sasse, _Proleg, in Aphr. Sapientis Persae sermones
homileticos_ (Leipzig, 1879); J. Forget, _De Vita et Scriptis
Aphraatis_ (Louvain, 1882); F.C. Burkitt, _Early Eastern Christianity_
(London, 1904); J. Labourt, _Le Christianisme dans l'empire perse_
(Paris, 1904); J. Zahn, _Forschungen_ I.; "Aphraates and the
Diatessaron," vol. ii. pp. 180-186 of Burkitt's _Evangelion
Da-Mepharreshe_ (Cambridge, 1904); articles on "Aphraates and
Monasticism," by R.H. Connolly and Burkitt in _Journal of Theological
Studies_ (1905) pp. 522-539; (1906) pp. 10-15. (N. M.)