"The two cerebral hemispheres are asymmetrical; in the region where the parieto-occipital fissure is situated on the left hemisphere, the two hemispheres diverge from each other and form an edge which curves outward and backward, so that the cerebellum remains uncovered. On the lower surface of the frontal lobes there exists a strongly marked ethmoidal prominence. Neither of the fissures of Sylvius is quite closed, the left less so than the right; the operculum is but slightly developed, and the island of Reil lies with its fissures almost entirely uncovered. This conformation reminds us throughout of the brain of the anthropoid apes. The two sulci centrales sive fissuræ Rolandi run straight to the border of the hemisphere, less deeply impressed than is normally the case, without forming an angle with each other. Very strongly and deeply impressed sulci præcentrales seem to serve as substitutes for them. The sulcus interparietalis, which begins farther outward than in the ordinary human being, receives the sulcus parieto-occipitalis—a structure in conformity with the typical brain of the ape. The sulcus occipitalis transversus, which is generally lightly stamped in man, extends here as a deep fissure across over the occipital lobe, thus producing a so-called simian fissure, and the posterior part of the occipital lobe has the appearance of an operculum. The fissura calcarina has its origin directly on the surface of the occipital lobe, does not receive until late the fissura parieto-occipitalis, and goes directly, on the right side, into the fissura hippocampi. This abnormal structure also is typical for the brain of the ape.
"The gyrus occipitalis primus is separated from the upper parietal lobe by the sulcus parieto-occipitalis, a formation that, according to Gratiolet, exists in many apes. The gyrus temporalis superior is greatly reduced on both sides, and has an average breadth of only five millimetres; it is the one peculiarity that recalls emphatically the brain of the chimpanzee, which always has this reduced upper temporal convolution.
"We have here, then, a brain that scarcely deviates from the normal brain in volume, that possesses all the convolutions and fissures, seeming, perhaps, richer than the average brain in convolutions, and that is in every respect differentiated; and notwithstanding all this it approximates, in its whole structure, to the simian rather than to the human type. Had the brain been placed before me without my knowing its origin, I should have been perfectly justified in assigning this brain to an anthropoid ape standing somewhat nearer to man than does the chimpanzee."
No second case of this sort has thus far been observed.
[C.]
REPORTS CONCERNING THE PROCESS OF LEARNING TO
SEE, ON THE PART OF PERSONS BORN BLIND, BUT ACQUIRING
SIGHT THROUGH SURGICAL TREATMENT. ALSO
SOME CRITICAL REMARKS.
I. The Chesselden Case.
The following extracts are taken from the report published by Will. Chesselden in the "Philosophical Transactions for the Months of April, May, and June, 1728" (No. 402, London, pp. 447-450), or the "Philosophical Transactions from 1719 to 1733, abridged by J. Eames and J. Martyn" (vii, 3, pp. 491-493, London, 1734):
"Though we say of the gentleman that he was blind, as we do of all people who have ripe cataracts, yet they are never so blind from that cause but that they can discern day from night, and, for the most part, in a strong light distinguish black, white, and scarlet; but they can not perceive the shape of anything.... And thus it was with this young gentleman, who, though he knew these colors asunder in a good light, yet when he saw them after he was couched, the faint ideas he had of them before were not sufficient for him to know them by afterward, and therefore he did not think them the same which he had known before by those names....