86 
BULLETIN OF THE LABORATORIES 
That portion of the cortex within the gyrus fornicatiis is the stratum 
griseum circumvoluta of authors. The ectal tract of this convolution 
is the so-called lamina nuclearis. Meynert, with his usual morpholo- 
gical insight, recognized in the fascia dentata the free margin of the 
mesal portion of the manth. These relations are especially well seen 
in Plate XVIL of Honegger’s work. As Sala says, the sole difference 
between these gyri and other parts of the mantle consists in the fact 
that the cells are crowded into a single narrow layer. With the state- 
ments of Sala respecting the histological relations we are unable at 
present to agree, ist. That author describes the cells of the fascia 
dentata (gyrus uncinatus) as splenial. We think that, when the cell body 
is preserved, it differs from those of the gyrus fornicatus chiefly in size, 
but it lies in a different plane. We are furthermore unable to discover 
how the distinction between the protoplasmic and nerve process is 
made out in cases where they are so similar. 2d. Sala states that the 
large cells of the gyrus fornicatus are functionally connected with the 
fibres of the alveus, while the apical processes subdivide interminably 
and terminate in the processes of neuroglia cells. The nervous pro- 
cesses may spring from either end of the cells and either pass directly 
entad to the alveus or ectad to the fibre layer immediately adjacent 
and then return to jthe alveus. If the evidence of our sections is to be 
trusted, the apical fibres pass directly into the ectal tract while the op- 
posite extremity of the cell subdivides dichotomously, producing such 
a neuropilem as Sala himself figures, with which the alveus fibres may 
communicate. 
It seems scarcely to be doubted from the course of the radix lat- 
eralis that its fibres reach the surface of the hippocampus and connect 
either directly or indirectly with the ectal layer of this region. The 
great mass of the alveus fibres are derived from the ental aspect of the 
fascia dentata. Thus, according to our view, the lamina nuclearis and 
superficial bundle of the fascia dentata are parts of the tract from the 
radix lateralis. Strong confirmation of this suggestion is found in the 
much simpler relations in fishes. (See forthcoming paper in Journal 
of Comparative Neurology for December.) 
The Cerebral Cortex. 
The cortex of the precrucial lobe may be regarded as typically 
motor, but even here there are many cells of the ectal series which 
divide at once into two or more strong processes and these in turn 
again divide dicotomously until a dense felting of fibres develops over 
