[1] The ancient Via Aemilia, built in 109 B.C., led over this pass,
but originally turned east to Dertona (mod. _Tortona_).
[2] There are two separate lines from Sampierdarena to Ronco.
[3] This pass was also traversed by a nameless Roman road.
[4] This river (anc. Aesis) was the boundary of Italy proper in the
3rd and 2nd centuries B.C.
[5] The Monte Conero, to the south of Ancona, was originally an
island of the Pliocene sea.
APENRADE, a town of Germany in the Prussian province of Schleswig,
beautifully situated on the Apenrade Fjord, an arm of the Little Belt,
38 m. N. of the town of Schleswig. Pop. (1900) 5952. It is connected by
a branch line with the main railway of Schleswig, and possesses a good
harbour, which affords shelter for a large carrying trade. Fishing,
shipbuilding and various small factories provide occupation for the
population. The town is a bathing resort, as is Elisenlund close by.
APERTURE (from Lat. _aperire_, to open), an opening. In optics, it is
that portion of the diameter of an object-glass or mirror through which
light can pass free from obstruction. It is equal to the actual diameter
of the cylinder of rays admitted by a telescope.
APEX, the Latin word (pl. _apices_) for the top, tip or peak of
anything. A diminutive "apiculus" is used in botany.
APHANITE, a name given (from the Gr. [Greek: aphanes], invisible) to
certain dark-coloured igneous rocks which are so fine-grained that their
component minerals are not detected by the unaided eye. They consist
essentially of plagioclase felspar, with hornblende or augite, and may
contain also biotite, quartz and a limited amount of orthoclase.
Although a few authorities still recognize the aphanites as a distinct
class, most systematic petrologists, at the present time, have discarded
it, and regard these rocks as merely structural facies of other species.
Those which contain hornblende are uniform, fine-grained diorites,
vogesites, &c., while when pyroxene predominates they are ascribed to
the dolerites, quartz-dolerites, &c. Hence, any rock which is compact,
crystalline and fine grained, is frequently said to be _aphanitic_,
without implying exactly to which of the principal rock groups it really
belongs.
APHASIA[1] (from Gr. [Greek: a], privative, and [Greek: phasis],
speech), a term which means literally inability to speak, and is used to
denote various defects in the comprehension and expression of both
spoken and written language which result from lesions of the brain.
Aphasic disorders may be classed in two groups:--first, receptive or
sensory aphasia, which comprises (a) inability to understand spoken
language (auditory aphasia), and (b) inability to read (visual aphasia,
or _alexia_); second, emissive or motor aphasia, under which category
are included (a) inability to speak (motor vocal aphasia, or _aphemia_),
and (b) inability to write (motor graphic aphasia, or _agraphia_). It
has been shown that each of these defects is produced by destruction of
a special region of the cortex of the brain. These regions, which are
termed the speech centres, are, in right-handed people, situated in the
left cerebral hemisphere; this is the reason why aphasia is so commonly
associated with paralysis of the right side of the body.
A study of the acquisition of the faculty of speech throws light upon
the education of the speech centres, and helps to elucidate their
physiological interaction and the phenomena of aphasia. The auditory
speech centre is the first to show signs of functional activity, for
within a few months of birth the child begins to _understand_ spoken
language. Some months later the motor vocal speech centre begins to
functionate. The memories of the auditory word images which are stored
up in the auditory speech centre play a most important part in the
process of learning to speak. The child born deaf grows up mute. The
visual speech centre comes into activity when the child is taught to
read. Again, when he learns to write and thus begins to educate his
graphic centre, he is constantly calling upon his visual speech centre
for the visual images of the words he wishes to produce. From these
remarks it will be seen that there is a very intimate association
between the auditory speech centre and the motor vocal speech centre,
also between the visual speech centre and the graphic centre.
_Auditory Aphasia._--The auditory speech centre is situated in the
posterior part of the first and second temporo-sphenoidal convolutions
on the left side of the brain. Destruction of this centre causes
"auditory aphasia." Hearing is unimpaired but spoken language is quite
unintelligible. The subject of auditory aphasia may be compared to an
individual who is listening to a foreign language of which he does not
understand a word. Word deafness, a term often used as synonymous with
auditory aphasia, is misleading and should be abandoned. Auditory
aphasia commonly interferes with vocal expression, for the majority of
people when they speak do so by recalling the auditory memories of words
stored up in the auditory speech centre. _Amnesia verbalis_ is employed
to designate failure to call up in the memory the images of words which
are needed for purposes of vocal expression or silent thought.
_Visual Aphasia or Alexia._--The visual speech centre, which is located
in the left angular gyrus, is connected with the two centres for vision
which are situated one in either occipital lobe. Destruction of the
visual speech centre produces visual aphasia or alexia. Word blindness,
sometimes used as the equivalent of visual aphasia, is, like word
deafness, a misleading term. The individual is not blind, he sees the
words and letters perfectly, but they appear to him as unintelligible
cyphers. When the visual speech centre is destroyed, the memories of the
visual images of words are obliterated and interference with writing, a
consequence of _amnesia verbalis_, results. On the other hand, when the
lesion is situated deeply in the occipital lobe, and does not implicate
the cortex, but merely cuts off the connexions of the angular gyrus with
both visual centres, agraphia is not produced, for the visual word
centre and its connexion with the graphic centre are still intact (pure,
or sub-cortical word blindness).
_Motor Vocal Aphasia or Aphemia._--The centre for motor vocal speech is
situated in the posterior part of the third left frontal convolution and
extends on to the foot of the left ascending frontal convolution
(Broca's convolution). Complete destruction of this region produces loss
of speech, although it often happens that a few words, such as "yes" and
"no," and, it may be, emotional exclamations such as "Oh! dear!" and the
like are retained. The utterance of unintelligible sounds is still
possible, however, and there is neither defective voice production
(_aphonia_) nor paralysis of the mechanism of articulation. The
individual can recall the auditory and visual images of the words which
he wishes to use, but his memory for the complicated, co-ordinated
movements which he acquired in the process of learning to speak, and
which are necessary for vocal expression, has been blotted out. In the
great majority of cases of motor vocal aphasia there is associated
agraphia, a circumstance which is perhaps to be accounted for by the
proximity of the graphic centre. When the lesion is situated below the
cortex of Broca's convolution but destroys the fibres which pass from it
towards the internal capsule, agraphia is not produced (sub-cortical or
pure motor vocal aphasia). Destruction of the auditory speech centre is,
as we have seen, commonly accompanied by more or less interference with
vocal speech, a consequence of _amnesia verbalis_.
_Agraphia._--Discussion still rages as to the presence of a special
writing centre. Those who favour the separate existence of a graphic
centre locate it in the second left frontal convolution. It may be that
the want of unanimity as to the graphic centre is to be explained by an
anatomical relationship so close between the graphic centre and that for
the fine movement of the hand that a lesion in this situation which
produces agraphia must at the same time cause a paralysis of the hand.
Destruction of the visual speech centre by obliterating the visual
memories of words (_amnesia verbalis_) produces agraphia. Further,
several instances are on record in which agraphia has followed
destruction of the commissure between the visual speech centre and the
graphic centre. As already mentioned, agraphia is very often associated
with motor vocal aphasia.
A number of aphasic defects are met with in addition to those already
mentioned. Thus _paraphasia_ is a condition in which the patient makes
use of words other than those he intends. He may mix up his words so
that his conversation is quite unintelligible. In the most pronounced
forms he gabbles away, employing unrecognizable sounds in place of words
(_jargon and gibberish aphasia_). _Paragraphia_ is a similar defect
which occurs in writing. Both paraphasia and paragraphia may be produced
by partial lesions of the sensory speech centres or of the commissures
which connect these with the motor centres. _Object blindness_ (syn.
mind-blindness) refers to an inability to recognize an object or its
uses by the aid of sight alone. The probable explanation would seem to
be that the ordinary centre for vision has been isolated from the other
sensory centres with which it is connected. Not uncommonly there is
associated visual aphasia. _Optic aphasia_ was introduced to designate a
somewhat similar state in which, although the uses of an object are
recognized, the patient cannot name it at sight, yet, if it is of such a
nature that it appeals directly to one of the other senses, he may at
once be able to name it. _Tactile aphasia_, is a rare defect in which
there exists an inability to recognize an object by touch alone although
the qualities which, under normal circumstances, suffice for its
detection can be accurately described. _Amusia_, or loss of the musical
faculty, may occur in association with or independent of aphasia. There
is reason for believing that special receptive and emissive centres
exist for the musical sense exactly analogous to those for speech.
The speech centres are all supplied by the left middle cerebral artery.
When this artery is blocked close to its origin by an _embolus_ or
_thrombus_, total aphasia results. It may be, however, that only one of
the smaller branches of the artery is obstructed, and, according to the
region of the brain to which this branch is distributed, one or more of
the speech centres may be destroyed. Occlusion of the left posterior
cerebral artery causes extensive softening of the occipital lobe and
produces pure word blindness. Further, a tumour, abscess, haemorrhage or
meningitis may be so situated as to damage or destroy the individual
speech centres or their connecting commissures. The amount of recovery
to be expected in any given case depends upon the nature, situation and
extent of the lesion, and upon the age of the patient. Even after
complete destruction of the speech centres, perfect recovery may take
place, for the centres in the right hemisphere of the brain are capable
of education. This is only possible in young individuals. In the great
majority of instances the nature of the lesion is such as to render
futile all treatment directed towards its removal. In suitable cases,
however, the education of the right side of the brain may be very
greatly assisted by an intelligent application of scientific methods.
BIBLIOGRAPHY.--Broca, _Bulletin de la Societe anatomique_ (1861);
Wernicke, _Der Aphasische Symptomen-complex_ (Breslau, 1874);
Kussmaul, _Ziemssen's Cyclopaedia_, vol. xiv. p. 759; Wyllie, _The
Disorders of Speech_ (1895); Elder, _Aphasia and the Cerebral Speech
Mechanism_ (1897); Collins, _The Faculty of Speech_ (1897); Bastian,
_Aphasia and other Speech Defects_ (1898); Byrom Bramwell,
"Will-making and Aphasia," _British Medical Journal_ (1897); "The
Morison Lectures on Aphasia," _The Lancet_ (1906). See also the works
of Charcot, Hughlings Jackson, Dejerine, Lichtheim, Pitres, Grasset,
Ross, Broadbent, Mills, Bateman, Mirallie, Exner, Marie and others.
(J. B. T.)