244 Proceedings of the Royal Society 
or sinuses, and the elevation of the corresponding part of the 
outer table. 
These difficulties in the way of estimating the exact shape of 
the exterior of the brain, from an inspection of the outside of the 
head, were pointed out and discussed at the time when the phren- 
ological systems of Grail and Spurzheim were advocated in this 
city by George Combe and his disciples. 
But at that period an additional and even more important diffi- 
culty stood in the way of determining the exact relations of the 
outside of the brain to the outside of the skull, for the external 
configuration of the brain itself was not properly understood. 
Spurzheim had undoubtedly recognised that, in general form 
and direction, the convolutions of the human brain are “ remark- 
ably regular.” Thus he says — “ The transverse convolutions of the 
superior, lateral, and middle parts of the hemispheres are never 
found running in any other direction — never longitudinally, for 
example. Those that lie longitudinally again, as they do under 
the squamous suture, behind the temporal bone and on either side 
of the olfactory nerve, are never met with disposed transversely.”* 
His contemporaries Beil, Rolando, Foville, and Huschke had also 
directed attention to the constancy of individual convolutions. It 
was not, however, until the publication in 1854 of Gratiolet’s great 
work on the cerebral convolutions-}* that the surface of the cerebrum 
was so mapped out that definite descriptive names were applied, 
not only to the several lobes, but to the individual convolutions 
composing them, and the constancy of their position and relations 
to each other precisel} 7 determined. The study of Gratiolet’s work, 
and the adoption by so many anatomists of the greater number 
of his descriptive terms, have tended materially to advance our 
knowledge of the convolutions, and to make them more definite 
objects of physiological and pathological research. A need has 
therefore arisen for localising the position of the cerebral lobes and 
convolutions on the surface of the skull and head, and a method, or 
methods, of readily doing so is to be desiderated. In selecting 
names for four of the five lobes into which he subdivided each 
cerebral hemisphere, Gratiolet employed terms which expressed 
* The Anatomy of the Brain, translated by Willis, p. 111. London, 1826. 
f Memoires sur les Plis Cerebraux. Paris, 1854. 
