TRANSACTIONS OF THE 
ON TWO LITTLE-KNOWN CEREBRAL FISSURES, 
WITH SUGGESTIONS AS TO FISSURAL AND GYRAL 
NAMES. 
By BURT G. WILDER, M.D. 
In all adult human brains examined with reference to 
them in the anatomical laboratory of Cornell University, 
there have been found, more or less distinctly marked, two 
fissures which are seldom figured or described, but which 
probably have considerable morphological significance. 
The one indents the dorsimesal margin just cephalad of 
the precentral fissure and paracentral lobule. In the brain 
exhibited (from an adult mulatto) it is particularly distinct, 
and is shown in the outline figure in the N. Y. Med. Jour., 
Feb. 23, 1885, fig. 42. It seems to have been described by 
Lussana and Lemoigne (“ Fisiologia dei centri nervosi ence- 
falici,” Padova, 1871, fig. 177,) as Solco injiesso; paronym- 
ized, in Latin this becomes fissura infiecta, and in English the 
inflected fissure. At first glance it strongly suggests the 
cruciate fissure of the Carnivora, especially when the branches 
of the precentral border what resembles the sigmoid gyrus; 
but such a homology must not be admitted without further 
investigation. For some of the difficulties involved see the 
Transactions of this Association for 1883, p. 63. 
The other fissure is likewise well developed upon the brain 
exhibited, which was hardened within the skull by arterial 
alinjection, and hence escaped the injury and distortion which 
are sometimes inflicted upon the base, during the ordinary 
processes of removal and preservation. The fissure appears 
upon the meso-ventral aspect of the temporal lobe, near its 
tip, extending caudad for 1-3 cm. from the horizontal por- 
tion of the Sylvian, between the ventro-cephalic ends of the 
Reprinted from the Journal of Nervous and Mental Disease, Vol. xii., 
No. 3, July, 1885. 
350 351 
AMERICAN NEUROLOGICAL ASSOCIATION. 
hippocampal and collateral fissures. My attention was called 
to it this spring, and its constancy, and its relation to the 
Sylvian fissure and the insula led me to homologize it with 
the postsylvian portion of the fissure which, in the cat, for 
example, forms the dorso-lateral margin of the tract continued 
caudad from the olfactory lobe and crus. In man and 
other primates the great development of the insula and of 
the true cerebral portion of the hemisphere throws the fis- 
sure upon the ventro-mesal aspect, but, there is no essential 
change in its relations with the parts above named. Later 
I found that this homology had already been recognized by 
Owen and Broca in their naming of the fissures of the 
human brain. Owen's prior name is basirhinal; the name 
employed by me (“Anatomical Technology,” p. 496, and 
elsewhere) is postrliinal. If it can be shown to have a constant 
relation with a constant ental part, the amygdala, a name 
derived therefrom, like amygdaline, may be found preferable. 
As to the names of the fissures and gyres, on the assump- 
tion that, excepting the hippocampal, callosal, rhinal, 
and part of the Sylvian, all which have definite relations 
with ental structures, it may be long before the homologies 
between the primatial and carnivoral parts are satisfactorily 
determined, I make the following suggestions: 
1. That all the indentations of the cerebrum be called 
fissures (abbrev. F.), and this word be restricted thereto. 
2. That, excepting a few parts (insula, cuneus, proecuneus, 
paracentral lobule, uncus, subiculum, operculum, etc.) which 
have received special names, all the interfissural elevations 
be called gyres, Latin gyri (abbrev. G.), and that this word be 
restricted thereto. 
3. That, so far as possible, mononymic names for the 
fissures and gyri be selected from among those which are in 
use, or formed therefrom by substituting prefixes for words 
indicating relative position. 
4. That in a few cases ambiguous descriptive names be 
replaced by words indicative of position, relative to other 
parts having well-established names. 
5. That insula be preferred to lobus centralis, and central 
fissure to fissure of Rolando. NEUROLOGICAL TRANSACTIONS. 
352 
6. That the name Sylvian fissure be applied only to that 
portion of the human fissure which is commonly present 
among other mammals (the “ horizontal ” or “ posterior ” 
branch). 
7. That besides the true operculum (between the “ pos- 
terior ” and “ anterior ” branches of the “ Sylvian ”), three 
other opercula be recognized and designated by names 
indicative of relative position. 
In accordance with the above suggestions I have selected 
or formed the following names for the principal human fis- 
sures and gyri. The words here employed are the English 
paronyms of the corresponding Latin names. 
I. —Fissures, mainly or partly mesal. 
Callosal, supercallosal, inflected, paracentral, precuneal, 
occipital, medioccipital, suboccipital, calcarine, postcalca- 
rine, collateral, amygdaline. 
II. —Gyres, mainly or partly mesal. 
Callosal, paracentral lobule, precuneus, cuneus, postcalca- 
rine, subcalcarine, subcollateral, hippocampal, uncus, subic- 
ulum. 
III. —Fissures, mainly or partly lateral. 
Sylvian, presylvian, subsylvian, basisylvian, olfactory, 
triradiate, central, precentral, superfrontal, medifrontal, 
subfrontal, postcentral, parietal, supertemporal, subtem- 
poral, intermediate. 
IV. —Gyres, mainly or partly lateral. 
Operculum, preoperculum, suboperculum, postoperculum, 
insula, subfrontal, medifrontal, superfrontal, precentral, 
postcentral, parietal, marginal, angular, supertemporal, 
meditemporal, subtemporal, superoccipital, medioccipital, 
suboccipital.