EEKE 
The shape of an object is recognized best by a normal persons, near 
and in the point of fixation. Small shapes, comprising many details, 
the letters and words we read, are even exclusively perceived there 
and consequently seen with the fovea centralis. Everybody however 
may ascertain for himself that shapes, measuring 2 ¢.m. in diameter, 
will be recognized temporalward unto 40° in the periphery, if they 
are presented at a distance, equal to the distance of our point of 
distinct vision. 
When the light is bad, the recognizing of shapes in the periphery 
decreases very quickly in normal persons. Such is likewise the case, 
when through disease of the N. opticus, there is an important restriction 
of the field of vision. 
Our patient, presenting no abnormal fundus, no distur- 
bance in the perception of light, no blindness for letters or words 
(no alexia), no optical aphasy, and no other impediment for locali- 
zing with the eyes, than nystagmus when the eyes are fixed 
to the right, does not recognize shapes to the right, however large 
these shapes may be. This disturbance which incommodes him only 
very little, is first brought to his knowledge by the doctor. Then 
he ascertains its existence from the beginning: of his disease. 
In order to understand this disturbance, it will be necessary to 
take notice of the studies on alexia, made by Niessi von MAYENDOREF *). 
As the point of departure for his researches this investigator 
took two facts. | 
1. Letters and words are recognized only in the neighbourhood 
of the fovea centralis. 
2. Whenever bilateral occipital foci (tumour, softening) determine 
bilateral hemiopia, there remains a central field of vision, by means 
of which the patient is able to recognise small forms and colours 
and to read. On the basis of anatomical arguments, he then proceeds 
to construct these two propositions : 
1. the fovea centralis, projected on the cortex by a special 
bundle of fibres in the dorso-lateral strata sagittalia a, is localized in 
a separate cortical area. 
2. The destruction of these fovea-fibres or of this cortical area 
will determine alexia (blindness for letters and writing) either sub- 
cortical or cortical, 
he first part of this argumentation is not new, but the second 
part to a certain extent is. 
1) Erwin NiessL von Mayenporrr, Das Rindencentrum der optischen Wortbiider 
Arch. für Psychiatrie. Bd. 43 S. 633. 1908 and other communications e. g. 
Ueber eine directe Leitung etc, Wien Kl, Wockenschrift Nov. 1906. 
