of cortex characterized by the stripe of Gennari
occupies in man, as mentioned, the calcarine and cuneate region. It is
surrounded by a cortical field which, though intimately connected with
it by manifold conducting fibres, &c., is yet on various grounds
distinct from it. This field of cortex surrounding the visuo-sensory of
the calcarine-cuneate region is a far newer part of the neopallium than
the region it surrounds. Both in the individual (Flechsig) and in the
phylum (Bolton, Campbell, Mott) its development occurs far later than
that of the visuo-sensory which it surrounds. Flechsig finds that it has
no "projection" fibres, that is, that it receives none of the optic
radiations from the lower visual centres and gives no centrifugal fibres
in the reverse direction. This field encompassing the visuo-sensory
region differs from the latter in its microscopic structure by absence
of the lower layer of stellate cells and by the presence in it of a
third or deep layer of pyramidal cells (Mott). Its fibres are on the
average smaller than are those of the visuo-sensory (W.A. Campbell).
This zonal field is small in the lower apes, and hardly discoverable in
the dog. In the anthropoid apes it is much larger. In man it is
relatively much larger still. The impairment of visual memory and visual
understanding in regard to direction and locality is said to be observed
in man only when the injury of the cortex includes not only the
calcarine-cuneate region but a wide area of the occipital lobe. From
this it is argued that the zonal field is concerned with memories and
recognitions of a kind based on visual perceptions. It has therefore
been termed the _visuo-psychic_ area. It is one of Flechsig's
"association-areas" of the cortex.

Adjoining the antero-lateral border of the just-described _visuo-psychic
area_ lies another region separate from it and yet related to it. This
area is even later in its course of development than is the
visuo-psychic. It is one of Flechsig's "terminal fields," and its fibres
are among the last to ripen in the whole cortex. This terminal field is
large in man. It runs forward in the parietal lobe above and in the
temporal lobe below. Its wide extent explains, in the opinion of Mott,
the displacement of the visuo-sensory field from the outer aspect of the
hemisphere in the lower monkeys to the median aspect in man. To this
terminal field all the more interest attaches because it includes the
angular gyr