Freiburger historische Bestände - digital

182

Cunningham Memoirs.

inch long. The oscillations, therefore, exhibited in the lower corono-
Rolandic indices, looked at as a whole, are no doubt largely due to this.

But it may be asked : Is there any sexual difference to be observed in
the position of the coronal suture with reference to the fissure of Rolando ?
I believe that there is, although I must at the same time admit that the
number of heads examined with the view of determining this question do
not justify me in speaking decisively upon the point. It would appear,
however, probable, that the area of the frontal lobe covered by the parietal
bone is relatively greater in the female than in the male. In the specimens
which I have studied the fissure of Rolando was situated at a relatively
greater distance from the coronal suture in the female than in the male.
In the adult this difference was expressed by an upper corono-Rolandic
index of 16, and a lower index of 12*1 for the males as against an upper
index of 17*5, and a lower index of 13*9 for the females. Corresponding
differences were noted at the other stages of growth studied.

Before leaving this branch of my subject it is necessary to take note of
the work which has been done in the same field by Hamy, Foulhouze, Fdre\
Symington, and Poirier.

In an article published in 1872, Hamy makes the following extraordinary
statement :*—" Chez de jeune enfants dont la ligne suturale qui vient
d'etre nomine* differait assez peu dans son inclinaison de celle de l'adulte,
nous avons constate* que le sillon de Rolando passait en avant de 1'articulation,
de telle sorte que l'os frontal, dans ses parties laterales et inferieures, se
trouvait recouvrir une petite Vendue du lobe parietal." This supposed
forward position of the lower end of the fissure of Rolando he seeks to
associate with a feeble development in the infant of the third frontal
convolution. It is all the more necessary to contradict this statement,
seeing that Schwalbe appears to give some credence to it and has given it
a place in his standard work on " Neurologie" (p. 575). As we have
noted, the fissure of Rolando at no stage of its development lies in front of
the coronal suture. In two instances I have seen the lower end just touching
the sutural line, but these were cases in which it was in its earliest
stage, prior to the development of its upper piece.

Foulhouze examined a large number of subjects of different ages, but

* Revue d'anthropologic, p. 428.