Edward Anthony Spitzka 61 
tomoses caudally with an exoecipital (HOP”) segment. Its course is in 
general a simple one. , 
Four segments, of which three are tri-radiate, and one zygal, represent 
the meditemporal. The last-mentioned piece sends a ramus well across 
the subtemporal gyre, and a narrow isthmus separates it from the piece 
deseribed as confluent with the postealearine. 
The subtemporal is indifferently represented by four irregular ramified 
segments. 
The collateral is 8 em. in length and quite sinuous. Its apparent short- 
ness may be due to a division into two segments, the shorter cephalic one 
being confluent with a small postrhinal. 
GYRES OF THE TEMPORAL LOBE (LATERO-VENTRAL SURFACE).—Especially 
the supertemporal and to some degree the meditemporal gyres are narrow. 
The subtemporal is of the usual irregular contour, while the subcollateral 
is particularly wide in its middle portion owing to the divergence of the 
eollateral fissure. For the same reason the subcalearine gyre is very 
narrow in its middle portion but very broad, massive and richly fissured 
in its caudal part. 
Tuer InsutA.—The insula is small and of simple configuration present- 
ing the usual postinsular gyre and only three preinsular gyres. Owing to 
the slight development of the opereular parts the insular gyres are well- 
rounded, not fiattened as is usual when encroached upon by the parts 
which cover them. 
Rigut HEMICEREBRUM. 
THE INTERLOBAR FissuRES.—The Sylvian Fissure and its Rami.—The sylvian 
fissure is 5 cm. in length, ends in a simple manner without the usual 
episylvian or hyposylvian rami. Cephalad, and as described on the left 
side, the fissure opens out into a sylvian fovea. The depths of the fissure 
are as follows: Presylvian depth, 12 mm.; medisylvian depth, 16 mm.; 
postsylvian depth, 23 mm. 
Both the subsylvian and the presylvian rami are very short. The central 
fissure dips into the cleft to a depth of 8 mm. The basisylvian is only 15 
mm. in depth. 
Central Fissure—The central fissure attains a length of 10.5 em., is only 
slightly tortuous and, reaching the sylvian dips into the cleft to a depth 
of 8mm. On the mesial aspect, its dorsal end extends for 1 em. 
Occipital Fissure-—The occipital fissure is of exceedingly unusual form. 
At a point 2 em. from its origin at the occipito-calearine junction, the 
fissure appears to bifurcate, or what is probably a more correct deserip- 
tion, it actually ends here and joins an adoccipital and a postcuneal at 
once, for the relations of neither arm with the paroccipital justify calling 
the one or the other the true continuation of the occipital. 
Calcarine Fissure—The calearine fissure is 3 em. in length, and is sepa- 
rated from the postealearine by a narrow and slightly-depressed isthmus. 
‘The postealearine is a tri-radiate segment with a long dorsal limb. 
fod 
The occipito-calearine stem is 2.7 em.-in length and anastomoses ceph- 
