Freiburger historische Bestände - digital

254

Cunningham Memoirs.

brain in man," he shows conditions which are clearly cases of complete
union and complete separation of the horizontal and vertical portions of the
inferior prsecentral sulcus.* In the great majority of Sernoff's illustrations
the ramus horizontalis is indicated with clearness and exactitude {vide his
figs. 7 to 16, pp. 18 to 23, in which the different forms of the sulcus are
shown with great accuracy).

Fig. 56.—Sernoff's second type of prsecentral sulcus, p. r. i., sulcus praecentralis inferior ; p.r.s.,
prsecentralis superior; p. r. m., apparently a detached ramus horizontalis of the sulcus
praecentralis inferior.

The sulcus prsecentralis inferior is frequently connected with the sulcus
frontalis secundus. So common is this condition that Jensen was induced
to apply to the compound furrow arrangement thus produced the term of
"unterer Stirnfurchencomplex."f But, as Eberstaller has shown, although
it is more common to find the hinder end of the second frontal furrow
communicating with the prsecentral sulcus than free, in the great majority
of cases the union is not complete, seeing that a distinct deep annectant
gyrus is placed at the point of junction. In my study of this point I

* Individualniye tipy mozgovykh izvilin u tcheloveka. Hoskow, 1877.

f Die JAirchen und Windungen der menschlichen Grosshirn-Heinispharen, von Dr. Julius
Jensen, p. 14. Berlin, 1871.