Edward Anthony Spitzka Av 
FISSURES OF THE FRONTAL LOBE (LATERAL SURFACE).—The Precentral Fis- 
sural Complex.—This complex of fissures is of an extremely unusual ar- 
rangement, all its parts being independent of each other. First, the 
supercentral, essentially of zygal type, is situated unusually distant from 
the central, and anastomoses with the superfrontal only. Dorsad of the 
supercentral, is another fissure, simple and independent, and running 
about parallel with the central. The precentral seems to be made up of 
two segments, both of zygal type. The dorsal one is a true simple, non- 
anastomosing zygon. The ventral piece anastomoses with both the diag- 
onal and the subfrontal. The transprecentral, 2.3 em. in length, is inde- 
pendent, and does not dip deeply into the sylvian cleft. 
The diagonal is deep and has a common junction with the precentral 
and the subfrontal. 
The superfrontal may be traced uninterruptedly very far cephalad, 
nearly to the orbito-frontal, from which it is separated by a very narrow 
depressed isthmus. In the prefrontal region, the fissure passes some- 
what further laterad than usual, leaving the superfrontal gyre quite broad 
in this region. A series of fissural segments lying in the superfrontal 
gyre (paramesial fissures?) give, with the division of the medifrontal 
gyre, five fairly distinct frontal gyral tiers. 
The medifrontal fissure is very distinct, attains a length of 4.5 em., is 
richly ramified, and serves to divide the medifrontal gyre into two nearly 
equal tiers. The fissure does not anastomose with any other. 
The subfrontal fissure, 3.5 em. in length, bifureates cephalad and sends 
a long ramus into the subfrontal gyre corresponding in its position with 
the radiate fissure. 
The orbitofrontal is 5 ecm. in length, very well marked, tortuous and 
ramified. It joins an orbital fissure superficially. 
MESIAL SURFACE.—The supercallosal is in three segments separated 
from each other by very narrow isthmuses. The caudal segment is con- 
fluent with the paracentral. Cephalad, the supereallosal and frontomar- 
ginal fissures are arranged in so peculiar a manner that one is in doubt 
as to how to designate each segment. The appearance is one of duplica- 
tion similar to that observed hitherto by Manouvrier and others. 
The paracentral is simple, sweeping caudad gradually to appear on the 
dorsal surface for 12 mm. Cephalad it joins a segment of the supercal- 
josal. There is an independent longitudinal intraparacentral. 
The inflected is absent. 
Both the rostral and subrostral fissures are well marked; the former is 
5.5 em. in length, the latter 3.5 cm. 
ORBITAL SURFACE.—On the orbital surface, the fissures are complex. 
There is a lateral triradiate fissure, whose caudal limbs correspond with 
Weisbach’s “transverse orbital,’ and mesad of this lie a zygal and one 
sagittal fissure. The last-mentioned anastomoses with the orbitofrontal 
over a vadum. 
The olfactory fissure is 3.8 em. in length. 
GYRES OF THE FRoNTAL Lope (LATERAL SURFACE).—The precentral gyre, 
in general, is much wider than the postcentral gyre, but is unusually tor- 
tuous, and indented by numerous fissural rami. 
