TRANSACTIONS OF SECTION H. 601 
incisions, it presents for our consideration the following esential parts, some of 
which do not exist at all, and others are merely outlined, in the other Primates :— 
1. Suprasylvian Operculum.—Present in all Primates with definitely con- 
voluted brains, with the solitary exception of Chiromys, it is due to an expansion 
of the cortex situated above the suprasylvian sulcus, which made its appearance 
long before any opercular formation began.’ 
As the result of influences causally related to the flexion of the cerebral 
hemisphere, which reaches its maximum in the human brain, the suprasylvian 
sulcus undergoes a bending some distance behind the pseudosylvian sulcus. Thus 
it comes to pass that the suprasylvian operculum is subdivided into two parts ; 
(a) a direct part which remains superficial (the Rolandic operculum of authors), 
and (b) a reflected part which, becoming submerged, does not enter into the 
constitution of the superior lip of the sylvian complex (anterior part of the deep 
temporo-parietal annectant gyrus). 
2. Opercula of the Gyrus Reuniens.—‘The gyrus reuniens in the lemurs, as it 
is in the dog family, is altogether superficial. In the anthropoid apes its 
posterior part (the middle insula of Holl) alone is operculated. In man only 
is its anterior part (the anterior insula of Marchand) operculated ; although in 
certain very precious individual specimens of gorilla—and chimpanzee—brains 
we have been able to find the commencement of similar operculation. 
The operculum of the gyrus reuniens consists, in man, of two parts : (a) a 
posterior part, which is also found in the anthropoid apes (the Prerolandic oper- 
culum of authors); and (b) an anterior part characteristic of the human type 
(frontal operculum or cap de Broca). 
3. Holoperipheral Operculum.—Situated altogether behind, this operculum 
represents the operculation of a part of the peripheral territory itself. Its 
presence is the direct result of the bending of the suprasylvian sulcus (Post- 
rolandic operculum of authors). 
2. The Brain of the La Quina Fossil Man. 
By Professor Raout ANTHONY. 
The brain of the fossil man from La Quina, whose remains were discovered 
by Dr. Henri Martin on September 18, 1911, closely resembles those of Neander- 
thal, Gibraltar, and La Chapelle-aux-Saints. In all its dimensions, however, it 
is smaller than the Chapelle-aux-Saints brain, which seems to be due to a 
difference in sex, the latter being a man’s, whereas the La Quina bones are a 
woman’s remains. 
Like the brain of the Chapelle man the Quina brain is distinguished by its 
great length and flatness, but does not attain the same breadth as the former. 
The reduction of the anterior cerebral region is most marked. As in the Chapelle 
and Gibraltar brains the posterior parts of the cerebral hemispheres markedly 
overhang the cerebellum, and there is a noteworthy separation between the lateral 
lobes of the cerebellum. 
The measurements made to estimate the relative development of the different 
lobes of the cerebral hemispheres furnished figures practically identical with 
those obtained from the Chapelle brain. The frontal lobe in particular presents 
in relation to the other lobes a development intermediate to that found among 
the anthropoid apes (Simiide) on the one hand and modern men on the other 
(Frontal index: Simiide = 32:20: La Quina = 35-70: La Chapelle = 35-75: 
Modern Men = 43°30). 
The neopallial topography appears to have been equally similar to that of the 
man of La Chapelle. Upon the cast one can distinguish the traces of a broad 
and large frontal operculum or cap de Broca; and in the occipital region the 
traces of a very well-developed sulcus lunatus. 
2 For the identification of the suprasylvian sulcus among the Primates, see 
G. Elliot Smith, Descriptive and Illustrated Catalogue of the Physiological 
Series of Comparative Anatomy contained in the Museum of the Royal College 
of Surgeons of England, vol. ii., second edition, 1902; and ‘On the Morphology 
of the Brain in the Mammalia, with Special Reference to that of the Lemurs, 
Recent and Extinct,’ 7'ransactions of the Linnean Society of London, second 
series, Zoology, vol. viii., part 10, 432, and our own memoir, 1912. 
